True or false is the transformation of chemical energy to radiant and thermal energy when a flashlight is turned on is an example of inefficiency
4. A person can swim 0.65 m/s in still water. She heads directly south across a river 130 m wide and lands at a point 88 m [W] downstream. K/U T/I A (a) Determine the velocity of the water relative to the ground. (b) Determine the swimmer’s velocity relative to Earth. (c) Determine the direction she should swim to land at a point directly south of the starting point.
Answer:
speed of the person in still water = 0.65 m/s
width of the river = 130 m
distance covered downstream = 88 m
a) let the speed of the water be = s
The time to cover two displacements would be equal.
[tex] \frac{130m}{0.65m/s}=\frac{88m}{s}\\ \Rightarrow s = 0.44 m/s[/tex]
b) Swimmer's velocity relative to earth would be:
[tex] v = \sqrt{0.65^2+0.44^2} = 0.78 m/s[/tex]
c) The swimmer should swim south of East to land at a point directly south of the starting point.
In a hydrogen atom, the electron in orbit around the proton feels an attractive force of about 7.45 × 10−8 N. If the radius of the orbit is 5.89 × 10−11 m, what is the frequency? Answer in units of rev/s
The frequency of the speed of the electron is equal to 1.79 ×10¹⁶ s⁻¹.
What is the centripetal force?When an object having mass undergoes a uniform circular motion, then it is held by centripetal force in the circular path. The centripetal force can be expressed in the the following equation:
F = mω²R
where m is the mass of the object, 'v' and R are the speed and radius of the circular path respectively.
The angular frequency of the electron can be expressed as:
v = 2π f
Then the centripetal force will be equal to:
F = m (2π f)² R
F = m 4 π² f² R
[tex]f = \sqrt{\frac{F}{4\pi ^2m R} }[/tex]
Given, the attractive force of the nucleus and electron, F = 7.45 ×10⁻⁸ N
The radius of the orbit, r = 5.89 × 10⁻¹¹ m
[tex]f = \sqrt{\frac{7.45\times 10^{-8}}{4 \times (3.14)^2\times 9.1 \times 10^{-31}\times 5.89\times 10^{-11}} }[/tex]
f = 1.79 ×10¹⁶ s⁻¹
Therefore, the frequency of the linear speed of an electron is 1.79 ×10¹⁶ s⁻¹.
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how is a pure substance different from a mixture? A. mixtures can be separated by physical means B. Pure substances are made up of mixtures C. A pure substance is heterogeneous D. A mixture is made of one substance
Mixtures can be separated by physical means is the statement that describes how a pure substance different from a mixture.
A pure substance is a form of matter that has a definite (constant) composition and distinctive properties.
On the other hand, a mixture is a combination of two or more substances in which they retain their properties.
Any mixture can be formed and then separated by physical means into its pure components without changing the identity of those components.
That is, there are different methods to separate a mixture into its different components, these methods are physical since they do not alter the properties of the components.
These physical methods are: Filtration, decantation, distillation among others, and are based on the physical state, characteristics and properties of the components of the mixture, to use the most appropriate technique.
Therefore, we can conclude that mixtures can be separated by physical means is the statement that describes how a pure substance different from a mixture.
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All organisms contain ___ require it to survive
Answer:
Carbon
Explanation:
Carbon is one of the fundamental element that is present in organic compounds. The presence of carbon helps in the creation of a stable type of bond when combines with different elements. Two carbons can also form a bond by reacting with each other. So, it can create a larger and complex form of molecules. These compounds containing carbon are important as it carries out the various life-supporting processes.
This is why Carbon is very essential for the existence of life.
I'll give brainliest just please help me
If the distance between two objects decreases, then the force of gravity will
Select one:
a. decrease.
b. increase.
c. stay the same.
d. depends on the objects.
When forces on an object are balanced the object will
Select one:
a. move in a random direction.
b. move in the direction of the force.
c. not move.
d. depends on what the object is.
What type of force will cause an object to change its speed?
Select one:
a. balanced
b. unbalanced
c. strong
d. weak
Mass= 386g volume= 20cm3 what is the density=
The older, geocentric model of the solar system placed the__________ at the center. Today's heliocentric model places the________ at the center of the solar system.
Answer:
Earth
Sun
Explanation:
The heliocentric model opposes the geocentric model by placing the sun at the center of the solar system as opposed to the earth as it is with the geocentric model
Albert Einstein discovered the mathematical relationship between _____ and _____.
light
sound
energy
reactions
matter
Answer:
Energy and matter
Explanation:
Equivalence between energy and matter (mass) is given by:
[tex]E=mc^2[/tex]
It establishes that the equivalent energy of an object can be calculated as the product of its mass times speed of light. Given that the speed of light is a very big number, the formula implies that even a small object at rest contains a very high amount of energy.
Complete this sentence. If mass remains the same while the volume of a substance ________, the density of the substance will_______________. decreases, decrease increases, decrease increases, stay the same decreases, stay the same
Answer:
increases, decrease
Explanation:
The density of a body is the measure of mass concentration of a material. It is an intrinsic property which is constant. It is the ratio of mass and volume
m = Mass
v = Volume
Density
[tex]\rho=\frac{m}{v}[/tex]
This means that density is inversely proportional to volume.
So, if volume increases density will decrease.
How to find volume metric
Most of the asteroids in the solar system circle the Sun in a large ring, which is located immediately between the orbits of ________ and __________
the answer is Mars and Jupiter
WILL MARK BRAINLIEST AND THANKS | PLEASE HELP ASAP
Which of these is a similarity between a polar and a subtropical jet stream?
Both bring in cool air from the poles.
Both are formed at latitudes close to the poles.
Both are formed at latitudes close to the equator.
Both are formed at the boundary of warm and cool air masses.
Answer:
ccc
Explanation:
which of the following is not a process that forms metallic ore
I believe that this question has the following choices to choose from:
placer deposits
fossil compaction
hydrothermal solutions
igneous processes
Actually among all, I have never encountered an ore that formed due to fossil compaction. I suppose we can get minerals such as marble or lime but not ores. So the answer is:
fossil compaction (answer)
Your best answer is B
a stone is dropped from a cliff. after it has fallen 10m what is the stones velocity
Answer:
V=14,1421 m/s
Explanation:
it's simple.
Velocity increases with the gravity acceleration.
There's a formula called Torricelli's equation, and it is as it follows:
V^2 = Vo^2 +2.a.s
where V is the speed you wish to find
Vo is the initial speed
a is the acceleration, in this case, the gravity's one
s is the space it moved.
So, here we go
Vo=0
a=10 or 9.81 (some schools use 10 to simplify the math)
s=10
So, using g as 10
V^2 = 0 +2.10.10
V^2=200
V=14,1421 m/s
To calculate the object's speed, simply multiply the gravitational acceleration by the amount of time since release (or velocity). In other words, velocity is equal to -9.81 m/s2 * time, or V = gt.
What velocity of stone dropped from a cliff?When dropped, a rock or other object will pick up speed quickly. According to measurements, an object falling 1 foot (ft) will move at a speed of 8.02 feet per second (ft/s).
A 4 ft (1.22 m) drop causes an object to travel at a speed of 16.04 ft/s. The velocity obtained is 22.70 ft/s after an 8-foot descent. When a stone is hurled upward, its velocity will be zero as it reaches its highest point, since the stone briefly comes to rest there.
Therefore, The final speed in a descending direction is 14 meters per second.
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6. Velocity is a ____________. a) vector b) value c) arrow d) none of these
Which is larger than a single atom?
a. magnetic domain
b. electron
c. neutron cloud
d. proton
Answer:
c
Explanation:
which type of friction keeps a mound of rocks from falling away from each other
a) rolling friction
b) static friction
c) cohesive friction
d) kinetic friction
b) static friction
Static means "not moving." So friction that is static is friction that keeps things from moving.
In the past, the intensity of the Earth's magnetic field was _____. A. greater B. weaker C. same D. evidence is inconclusive?
I'm sure A is the right answer
the theory that all matter consists of constantly moving particles is known as the
a. physical theory of matter
b. attraction theory of matter
c. theory of states of matter
d. kinetic theory of matter
How would you measure the volume of a sponge
how to find the acceleration
1. A goal is scored in soccer when_____. (1 point) the ball hits the outside of the net the ball crosses the goal line the ball hits the goal post none of the above 2. The _________ pass is used when a player wants to make a short, quick, and accurate pass in soccer. (1 point) 3. Name the term in soccer that is used when a player stops a pass at his/her feet. (1 point) Dribbling Passing Trapping Punting 4. What is the term for when a player stops the soccer ball with their foot? (1 point) 5. What is the term in soccer for when a player moves the ball into the goal post past the goalie? (1 point) Shooting Dribbling Trapping Punting 6. Which of the following soccer skills is employed only by the goalkeeper? (1 point) Punting Shooting Dribbling None of the above 7. Which of the following soccer skills can be dangerous if performed incorrectly? (1 point) Punting Trapping Dribbling Heading 8. Which of the following soccer terms shares its name with a popular basketball term? (1 point) Punting Heading Trapping Dribbling 9. How is play resumed in soccer when the ball goes out of bounds? (1 point) Throw-in Free throw Goal kick Instep pass 10. Which type of trap is used to stop a ball at waist level? (1 point) Foot trap Chest trap Thigh trap
2 is an instep if im not mistaken
Which of the following is true for gravitational force?
Decreases with increase in mass
Increases with increase in mass
Increases with increase in distance
Decreases with decrease in distance
The answer is b increases in increase of mass because the heavier the object is the more gravitional pull it will have. For example, what will fall faster? A 1 pound object or a 10 pound obect.
Answer:
B because I took the test and got it correct.
Inertia increases as an object's _________ increases. mass volume acceleration velocity
The main offenders in terms of greenhouse gas emissions
If two automobiles have the same velocity, do they have the same acceleration? Why, or why not.
Even if two cars have the same velocity, they might not have the same acceleration. Acceleration is the rate at which velocity changes, so the cars could be accelerating or decelerating at different rates even though their velocities are the same.
Explanation:Two automobiles having the same velocity does not necessarily mean they have the same acceleration. Acceleration is the rate of change of velocity of an object with respect to time. So, if two automobiles have the same velocity at a particular moment, it doesn't provide any information about their rates of change of velocity. Think about it this way: two cars might be moving at 60 miles per hour, but one might be speeding up while the other is slowing down. Therefore, they would have different accelerations even though their velocities are the same.
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how does light determine whether it acts as a particle or a wave?
what are ten derived quantities
PLEASE HELP!!
Location X and Y are adjacent. Location X has a lower air pressure than Location Y. What will most likely happen?
Wind will blow from one location to another.
Air above Location Y will rise up and condense.
Temperature at the two locations will become equal.
Convection currents of air above the two locations will stop.
It is A. Wind Blow from one location to another.
Answer:
its A
Explanation: