Heat transfer from one substance to another results in the decrease of temperature in the substance losing heat and an increase in the substance gaining heat. At the melting or boiling points, heat absorbed is used for phase changes instead of raising the temperature. The heat required for a phase change is proportional to the substance's mass.
When heat flows from one substance to another, this process is known as heat transfer. The substance giving off heat, or the higher temperature substance, will experience a decrease in its temperature. Conversely, the substance receiving the heat, or the cooler substance, will see an increase in temperature. This heat transfer continues until both substances reach thermal equilibrium, meaning they have the same temperature.
Specifically, at the melting point or boiling point, heat flow into a substance does not change its temperature but rather is used to change its state. This is because the energy is utilized to break the intermolecular forces that hold the substance in its current phase. For example, when ice melts to become water at its melting point, the temperature remains constant until all the ice has melted. The same is true for boiling; the temperature of the liquid remains constant during the transition to a gas.
The amount of heat required for these phase changes is directly proportional to the mass of the substance undergoing the change. In other words, larger amounts of substance will require more heat to complete the phase transition.
The refractive index of water is greater than that of air but is less than that of glass or a diamond. under which condition can there be total internal reflection in water?
To ensure 100% internal reflection in water, the light must first pass through glass or a diamond before entering the water.
What is an index of refraction?The refractive index of a substance also known as the refraction index or index of refraction is a dimensionless quantity that specifies how quickly light passes through it in optics.
The speed at which light waves travel changes as the medium changes. The absolute refractive index changes.
Angle of incidence must be larger than critical angle for entire internal reflection.
Total internal reflection occurs in water when the refractive index on the other side of the water is lower and the angle of incidence is larger than the critical angle.
So there must be oxygen on the other side of the river. Light must go from a medium object of greater density to a medium object of lower density for total internal reflection to occur.
To ensure 100% internal reflection in water, the light must first pass through glass or a diamond before entering the water.
In the water, the angle of incidence is 50 degrees. It experiences entire internal reflection because the angle of incidence is larger than the air-water critical angle of roughly 48°.
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Which statement is not true about electrons? Electrons have a negative charge. The orbit of electrons around the nucleus is like a cloud. The path an electron moves on is not very straight. The basic unit of matter is the electron.
Answer:
The basic unit of matter is the electron.
Explanation:
Electrons have a negative charge.
Above statement is true because electron is a negatively charged particle and its charge is given as e = [tex]-1.6 \times 10^{-19} C[/tex].
The orbit of electrons around the nucleus is like a cloud.
Above statement is true as electron forms a cloud around the nucleus and that cloud is known as orbit of electron.
The path an electron moves on is not very straight.
Above statement is true as Electron moves around the nucleus in closed loop and in this path centripetal force is given by electrostatic attraction force
The basic unit of matter is the electron.
Above statement is not correct as we know that basic unit of matter is not electron but it consist of electron, neutron and proton
A 40.0 kg crate is being lowered by means of a rope. Its downward acceleration is 3.80 m/s2. What is the force exerted by the rope on the crate? A 40.0 kg crate is being lowered by means of a rope. Its downward acceleration is 3.80 m/s2. What is the force exerted by the rope on the crate?
Final answer:
The force exerted by the rope on the crate is 152.0 N.
Explanation:
To calculate the force exerted by the rope on the crate, we can use Newton's second law of motion, which states that force is equal to mass times acceleration. In this case, the mass of the crate is 40.0 kg and the acceleration is 3.80 m/s². Therefore, the force exerted by the rope on the crate can be calculated as:
Force = mass * acceleration
Force = 40.0 kg * 3.80 m/s²
Force = 152.0 N
Therefore, the force exerted by the rope on the crate is 152.0 N.
A compressed spring has 16.2 J of elastic potential energy when it is compressed 0.30 m. What is the spring constant of the spring?
Answer:
360
Explanation:
just took the test
Final answer:
To find the spring constant, use the formula for elastic potential energy,[tex]U = 1/2 k x^2[/tex]. Given that U = 16.2 J and x = 0.30 m, the spring constant is calculated to be 360 N/m.
Explanation:
The spring constant, denoted by k, is a measure of the stiffness of a spring. It represents the force required to stretch or compress a spring by a certain amount.
The question asks about finding the spring constant from the given elastic potential energy and displacement.
The formula for elastic potential energy stored in a spring is [tex]U = 1/2 k x^2[/tex], where U is the elastic potential energy, k is the spring constant, and x is the displacement from the equilibrium position. Using this formula and the given values, we can solve for k as follows: [tex]16.2 J = 1/2 k (0.30 m)^2[/tex]. After calculating, we find the spring constant is 360 N/m.
If a molecule has an unequal distribution of charge in its internal structure, it is said to be _____.
A: saturated
B: unsaturated
C: polar
D: nonpolar
what is necessary condition for the conservation of momentum?
Final answer:
The necessary condition for conservation of momentum is the absence of net external forces on the system, making it closed or isolated. In this state, the total momentum remains constant, which is fundamental in solving physics problems related to the motion of objects.
Explanation:
The necessary condition for the conservation of momentum is that there should be no net external force acting on the system. In physics, this is known as an isolated system or a closed system. When analyzing problems using the conservation of momentum principle, it is crucial to identify whether the system in question meets this condition. In such a system, the vector sum of all the momenta remains constant. This is because, according to Newton's Second Law, when there is no net external force, there would be no change in the momentum of the system. Even in the presence of internal forces, like during a collision between particles, as long as the net external force is zero, the total momentum before and after an event remains the same.
To apply the conservation of momentum, the first step always involves confirming that you're dealing with a closed system with no net external force. This means even with forces like friction or air resistance, if they are considered external, they must be negligible or balanced out by other forces to maintain conservation of momentum.
The light bulbs in an office building give off tremendous amounts of heat. Since heat is a form of energy, this heat could be trapped and used to offset our need for electricity, thus saving energy and money. True False
Answer:
False
Explanation:
The office area where night bulbs are used is very large and the light bulbs used do not produce this much amount of energy which can be trapped and used to offset our need for electricity.
This energy generated from these bulb is only a waste as it cannot be converted into reusable form. It can only be dissipated as heat.
A mass m = 4.6 kg hangs on the end of a massless rope L = 2.16 m long. The pendulum is held horizontal and released from rest.
1)How fast is the mass moving at the bottom of its path?2)What is the magnitude of the tension in the string at the bottom of the path?
ind the velocity my using the conservation of energy mgh=1/2mv^2. At the bottom, the mass is turning in a circle with tension pointing up towards the center of the circle and weight pointing down. Use the centripetal force requirement mv^2/r=T-W and solve for T. Hope this helps.
The speed of the mass at the bottom of its path is approximately 6.51 m/s, and the tension in the string at that point is approximately 141.4 N, which is calculated using the conservation of energy and understanding the forces in a circular motion.
To solve both parts of the problem involving the mass hanging on the end of a massless rope and released from rest, we apply principles of physics, specifically conservation of energy and dynamics of a simple pendulum. Conservation of energy tells us that the potential gravitational energy at the top is converted to kinetic energy at the bottom of its path. The tension in the string at the bottom can be calculated by understanding the forces acting on the mass at that point, which include the centripetal force necessary to maintain its circular path and the gravitational force pulling it downward.
Using conservation of energy, we have:
Potential Energy at top (U): U = mgh = mgL
Kinetic Energy at bottom (K): K = 1/2 m[tex]v^2[/tex]
Setting U equal to K gives us:
mgL = 1/2 m[tex]v^2[/tex]
From which we can solve for v, the speed at the bottom:
v = [tex]\sqrt{2gL}[/tex]
Substituting in the values (g = 9.8 m/[tex]s^2[/tex], L = 2.16 m),
v = [tex]\sqrt{2 \times 9.8 \times 2.16} = \sqrt{42.336} \approx 6.51 m/s[/tex]
The tension in the string (T) at the bottom is the sum of the gravitational force and the centripetal force required to keep the mass moving in a circle:
T = mg + m[tex]v^2[/tex]/L
Substituting in the known values:
T = 4.6 × 9.8 + 4.6 × [tex](6.51)^{2/2.16}[/tex]
T = 45.08 + 4.6 × (42.3961)/2.16
T = 45.08 + 96.3273
T = 141.4073 N
The tension at the bottom of the path is approximately 141.4 N.
If we want to describe work, we must have
an action which causes no movement or reaction.
a force and a movement in the opposite direction of the force.
a force and a movement in the same direction as the force.
an action which causes movement and an opposite reaction.
Answer:
The answer is C. A force and a movement in the same direction as the force.
Explanation:
Work is one of the forms of energy transmission between bodies where work is the product of a force applied to a body and the displacement of the body in the direction of this force, that is, Work is the product of the distance traveled by a body by the value of the force applied at that distance. When work is done on the body, there is a transfer of energy to it.
What net force is required to push a sofa with a mass of 59 kilograms so that it accelerates at 9.75 meters/secondÆ? (Assume a flat, frictionless surface.)
A. 6.1 Newtons
B. 59 Newtons
C. 5.8 x 10^2 newtons
D. 6.0 x 10^2 newtons
Answer : [tex]F=5.8\times 10^2\ Newtons[/tex] amount of force is required to push a sofa.
Explanation :
It is given that,
The mass of sofa, m = 59 kg
Acceleration, [tex]a=9.75\ m/s^2[/tex]
According to Newton's second law of motion :
F = ma
m is the mass and a is the acceleration produced.
[tex]F=59\ kg\times 9.75\ m/s^2[/tex]
F = 575.25 Newtons
[tex]F=5.75\times 10^2\ Newtons[/tex]
or
[tex]F=5.8\times 10^2\ Newtons[/tex]
Hence, this is the required solution.
Some simple Machines decrease mechanical advantage and are used to_______.
1.) decrease work
2.) divide distance to decrease speed
3.) multiply distance to decrease speed
4.) increase work
3.) multiply distance to increase speed
Some simple Machines decrease mechanical advantage and are used to multiply distance to decrease speed , therefore the correct answer is option 3.
What is the mechanical advantage?Mechanical advantage is defined as a measure of the ratio of output force to input force in a system, It is used to analyze the forces in simple machines like levers and pulleys.
Mechanical advantage = output force(load) /input force (effort)
Thus, Some simple Machines decrease mechanical advantage and are used to multiply distance to decrease speed, therefore the correct answer is option 3.
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The distance between Miami and Oriando is about 220 miles .A pilot flying from
Miami to Orlando start the flight 10 degree off course to avoid a storm.
a) After flying in this direction for 100 miles , how far is the plane from Orlando?
b)If the pilot adjust his course after 100 miles , how much farther is the flight
than a direct route?
Using trigonometric functions, we can calculate the plane's distance from Orlando after deviating from the course and the extra distance flown after correcting course back towards Orlando.
Explanation:To solve the problem regarding the pilot's flight from Miami to Orlando, we will employ trigonometric concepts to determine the distance of the plane from Orlando after flying 100 miles off course and to calculate how much farther the flight would be than a direct route after the course correction.
a) After flying 100 miles at 10 degrees off course, we can use right triangle trigonometry to find the distance from Orlando. We know the adjacent side (100 miles of flight) and the angle (10 degrees); we are interested in finding the hypotenuse, which represents the distance from the starting point, and the opposite side, which will represent the deviation from the direct path towards Orlando. Using the cosine function, cos(10 degrees)=adjacent/hypotenuse=100/hypotenuse, we can solve for the hypotenuse. Then, using the sine function, sin(10 degrees)=opposite/hypotenuse, we can solve for the opposite side, which, when subtracted from the original 220 miles, will give us the remaining distance to Orlando.
b) If the pilot adjusts course after 100 miles, they will now have to fly not directly to Orlando but to the point they have deviated from their path. This forms another right triangle with one known side (the deviation) and another side that is part of the remaining distance towards Orlando. By applying the Pythagorean theorem, we can find the added distance by determining the hypotenuse of this new triangle and comparing it to the direct route that was 220 miles originally.
The plane is approximately 99.67 miles from Orlando after flying 100 miles in a direction 10 degrees off course. If the pilot adjusts the course, the total distance of the flight will be approximately 218.28 miles farther than a direct route.
Explanation:To determine the distance the plane is from Orlando after flying in a direction 10 degrees off course for 100 miles, we can use trigonometry. Since the plane is 10 degrees off course, we can create a right triangle where the hypotenuse represents the plane's actual distance from Orlando and the adjacent side represents the distance the plane has traveled. Using the cosine function, we can calculate that the plane is approximately 99.67 miles from Orlando.
If the pilot adjusts the course after flying 100 miles, the total distance of the flight will be the sum of the straight-line distance from Miami to Orlando and the additional distance traveled in the adjusted course. To find the additional distance, we can use the Pythagorean theorem to calculate the length of the hypotenuse of a right triangle where one side is the straight-line distance from Miami to Orlando (220 miles) and the other side is the distance the plane has traveled (100 miles). The additional distance will be approximately 218.28 miles.
This law states that a planet's elliptical orbit around the Sun sweeps equal amounts of area in an equal amount of time. This means that each planet travels faster near the Sun and slower farther from it.
A. law of ellipses
B. law of inertia
C. equal areas law
D. harmonic law
The law is C.) Equal areas law
A hot-air balloon is 150 feet above the ground when a motorcycle passes directly beneath it (traveling in a straight line on a horizontal road). The motorcycle is traveling at 40 mph. If the balloon is rising vertically at a rate of 10 ft/sec, what is the rate of change of the distance between the balloon and the motorcycle ten seconds later?
the pitch of a sound us most closely related to the
How does physical change affect the identity of a substance
Physical changes involve alterations that do not change the identity of a substance. They are primarily visible and include changes in shape, size, color, or state. Despite these changes, the substance's core identity and chemical properties remain unaltered.
Explanation:In chemistry, a physical change involves alterations that are primarily visible and do not change the inherent properties or identity of a substance. Examples of physical changes can include changes in shape, size, color, or state of matter (like water freezing or boiling).
When a substance undergoes a physical change, it does not change into a new substance. The identity of the substance remains the same before and after the change. For instance, when an ice cube (solid water) melts, it becomes liquid water. Despite this change in state, it is still fundamentally water and has the same chemical properties.
Therefore, physical changes affect a substance in a visual or tangible way, but they do not alter the core identity of a substance.
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Answer the following question about "The Deadliest Tsunami in History."
Survivors of the Tsunami recognized that a receding ocean
a. Was a sign of danger
b. Left pollution on shore
c. Left boats and fish stranded on shore
d. Signals a coming earthquake
The correct answer is - a. was a sign of danger.
Once the people saw that the ocean waters are receding and were living vast space without water behind them, they knew that something big and very dangerous will happen. And in fact it did. The water that was sucked in in the place were there was a crack on the ocean floor, got shot back under big pressure and it had very big speed, as well as having waves that were destroying anything on their way.
Answer:
Option (A)
Explanation:
Tsunamis are the series of large waves that are generated in the large water bodies such as seas and oceans, due to an earthquake, underwater explosion or landslide. These waves can rise up to a height of about hundreds of meters.
A receding ocean is a sign of danger that signifies that a tsunami is approaching. During this time the water level drops down unusually along the coastline. It is a kind of warning that is given to the people living in the coastal areas to evacuate it as soon as possible in order to save their lives.
Thus, the correct answer is option (A).
1. With manual transmission, use your right foot for the brake and accelerator and left foot for the clutch. true or false
Heat moves through liquid and circulates due to density A. radiation B. conduction C. Convection D. water cycle A.radiation When the electromagnetic radiation in a region of space is at equilibrium with its surroundings, it can be described by the Planck radiation formula. [ The total energy radiated from an area in this region of space is given by the Stefan-Boltzmann law and the energy density associated with the radiation can be related to that law. In the development of the expression for the
I believe the correct answer would be c
Heat transfer through the movement of fluid due to temperature-induced changes in density is known as convection.
Heat transfer by circulation of a fluid is known as convection. This process takes place when fluid, such as air or water, is heated and then moves due to changes in density. Hotter, less dense fluid rises, while cooler, denser fluid sinks, creating a circulation that effectively transfers heat within the fluid. For instance, when heating a pot of water, the heat is conducted to the water at the bottom of the pot. This heated water then expands, making it less dense than the surrounding cooler water, causing it to rise. As it rises, cooler water then moves down to replace it, and this cyclical process continues, resulting in the transport of heat throughout the pot by convection.
A student throws a baseball horizontally at 25 meters per second from a cliff 45 meters above the level ground. Approximately how far from the base of the cliff does the ball hit the ground? [neglect air resistance.]
The baseball hits the ground approximately 75.8 meters from the base of the cliff. This is calculated using physics principles of gravity and projectile motion, considering the height of the cliff, acceleration due to gravity, and the horizontal velocity of the baseball.
Explanation:This question involves what is called projectile motion, which is a topic in physics. To find the horizontal distance from the base of the cliff where the ball hits the ground, we need to know the time it takes for the ball to fall. Incidentally, the horizontal velocity doesn't affect this; it will take the same amount of time to hit the ground whether it's thrown horizontally or simply dropped.
We know the acceleration due to gravity is 9.8 m/s². The time it takes for the ball to hit the ground can be calculated using the formula: t = √(2h/g), where h is the height and g is the acceleration due to gravity. Substituting 45m for h and 9.8m/s² for g gives: t = √(2*45/9.8) which equals about 3.03 seconds.
In this time, the ball will move horizontally at 25 m/s for 3.03 seconds, a total of about 75.8 meters. So, the ball hits the ground approximately 75.8 meters from the base of the cliff. This is assuming negligible air resistance.
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What happens when the temperature of an object increases?
A.
The particles move closer together.
B.
The particles move faster.
C.
The number of particles increases.
D.
The particles stop moving.
Use your periodic table to answer the following question.
How many valence electrons are there in Lithium (Li)?
2
1
3
4
Answer:
The real answer is A. 1
Explanation:
Help!!!! Please..... Someone. Problem:
Starting with an initial speed of 5.00 m/s at a height of h = 0.260 m, the m1 = 1.55 kg ball swings downward and strikes the m2 = 4.50 kg ball that is at rest, as the drawing shows.
(a) Using the principle of conservation of mechanical energy, find the speed of the 1.55-kg ball just before impact.
(b) Assuming that the collision is elastic, find the velocities (magnitude and direction) of both balls just after the collision.
(c) How high does each ball swing after the collision, ignoring air resistance? ...?
Answer:
Part a)
[tex]v_f = 5.48 m/s[/tex]
Part b)
[tex]v_1 = -2.67 m/s[/tex]
[tex]v_2 = 2.81 m/s[/tex]
Part c)
[tex]h_1 = 0.36 m[/tex]
[tex]h_2 = 0.40 m[/tex]
Explanation:
Part a)
As we know by energy conservation law
initial kinetic energy + initial potential energy = final kinetic energy + final potential energy
So here we know that
[tex]\frac{1}{2}mv_i^2 + mgh_i = \frac{1}{2}mv_f^2 + mgh_f[/tex]
[tex]v_i = 5 m/s[/tex]
[tex]h_i = 0.260 m[/tex]
[tex]h_f = 0[/tex]
now we have
[tex]v_f^2 = v_i^2 + 2gh[/tex]
[tex]v_f^2 = 5^2 + 2(9.8)(0.260)[/tex]
[tex]v_f = 5.48 m/s[/tex]
Part b)
As we know that collision is perfectly elastic collision
so we will have
[tex]m_1v_{1i} + m_2v_{2i} = m_1v_{1f} + m_2v_{2f}[/tex]
[tex]1.55(5.48) + 0 = 1.55 v_1 + 4.50 v_2[/tex]
also we know for elastic collision
[tex]v_2 - v_1 = 5.48[/tex]
[tex]v_1 = -2.67 m/s[/tex]
[tex]v_2 = 2.81 m/s[/tex]
Part c)
Now the height of each ball is given by
[tex]h = \frac{v^2}{2g}[/tex]
[tex]h_1 = \frac{2.67^2}{2(9.81)}[/tex]
[tex]h_1 = 0.36 m[/tex]
[tex]h_2 = \frac{2.81^2}{2(9.81)}[/tex]
[tex]h_2 = 0.40 m[/tex]
The student's question involves applying the conservation of mechanical energy to find the speed of a ball before impact, using the conservation of momentum and kinetic energy for an elastic collision, and determining the height of the swing post-collision in physics.
Explanation:To solve the student's problem, we will apply the principles of conservation of mechanical energy and conservation of momentum which are fundamental concepts in physics, specifically in the field of mechanics. Given the nature of the questions, this falls into the category of a high school physics problem, typically encountered by students learning about motion and energy.
Conservation of Mechanical EnergyFor part (a), the conservation of mechanical energy states that the total mechanical energy (kinetic plus potential) in an isolated system remains constant if only conservative forces are acting. Initial mechanical energy at the height h will be equal to the kinetic energy just before the impact.
Elastic CollisionFor part (b), an elastic collision is one where both momentum and kinetic energy are conserved. We would apply both the conservation of momentum and kinetic energy equations to find the velocities of the two balls post-collision.
Height of Swing After CollisionFor part (c), after the collision, to find how high each ball swings, we would convert the kinetic energies of the balls just after the collision to potential energies at the peak of their respective swings, assuming no energy is lost to air resistance.
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Parallax of the stars is created by
A. different phases of the moon
B. different locations of Earth in its orbit
C. motion of the stars ...?
Describe several uses of plastic, and explain why plastic is a good choice for these products
What is Newton's Third Law of Motion?
Help! Elastic Collision.
Two objects, one initially at rest, undergo a one-dimensional elastic collision. If half the kinetic energy of the initially moving object is transferred to the other object, what is the ratio of their masses? ...?
In the case of a one-dimensional elastic collision where half the kinetic energy is transferred from one object to another initially at rest, the mass ratio between the moving and stationary objects is 3:1, derived from principles of kinetic energy and momentum conservation.
Explanation:The question relates to finding the mass ratio of two objects in a one-dimensional elastic collision where half of the kinetic energy of the moving object is transferred to the initially stationary object. To arrive at the solution, we need to consider the principles of conservation of momentum and conservation of kinetic energy.
For elastic collisions, the total kinetic energy before collision is equal to the total kinetic energy after collision. If half of the kinetic energy of object 1 is transferred to object 2, and given that kinetic energy is proportional to the mass of the object and the square of its velocity (KE = 1/2 mv2), we can deduce that the kinetic energy ratio post-collision influences the mass ratio.
Here, the conservation of kinetic energy and the given condition imply a specific relationship between the masses, leading us to the conclusion that for half the kinetic energy to be transferred, the mass of the moving object must be three times that of the stationary object, yielding a mass ratio of 3:1. This result is derived from manipulating the formulas for kinetic energy and conservation of momentum to reflect the energy transfer condition.
Which statement correctly describes the relationship between current, voltage, and resistance? If we
A: decrease the resistance, and do not change the voltage, the current will decrease.
B: decrease the voltage, and do not change the resistance, the current will also decrease.
C: increase the resistance, and do not change the current, the voltage will remain the same.
D: increase the current, and increase the resistance, the voltage will decrease.
Answer: Option (b) is the correct answer.
Explanation:
According to ohm's law, the relationship between voltage, resistance, and current is that current passing through a conductor is directly proportional to the voltage over resistance.
Mathematically, I = [tex]\frac{V}{R}[/tex]
From this relationship we can see that when we decrease the voltage, and do not change the resistance, the current will also decrease. As current is directly proportional to voltage and inversely proportional to resistance.
Which of the following statements is true about the movement of sound waves?
A. they can only travel through a vacuum
B. they can travel through air only
C. they can only travel through a medium
D. they travel fastest in gaseous mediums
Answer: The correct option is C.
Explanation:
Longitudinal wave is a wave in which the particles vibrates parallel to the direction of the energy transportation of the wave .
For example, sound wave.
Sound wave consists of rarefaction and compression. In rarefaction, the density of the particles is more in comparison to compression.
Sound wave needs a medium for its propagation. It can travel in solid, liquid and gas. It cannot travel in vacuum.
Therefore, the true statement about the movement of sound waves is only (C) option.
Two friends, Joe and Sam, go to the gym together to strength train. They decide to start off with an exercise called flat bench press. Lying flat on a bench with their arms in an extended position, they slowly lower (to their chest) and then raise a barbell back to the starting position. They start off by using a 45.0 kg barbell. Joe is taller than Sam which means Joe\'s arms are 69.4 cm long while Sam\'s are 60.6 cm. Calculate the work done by Joe, WJoe, when he raises the barbell to finish one repetition. The acceleration due to gravity is 9.81 m/s3