Please help on this one?

A) The forward force is equal to the backward force

In this problem:

- the forward force is the force that Megan applies to the pedal to go forward

- the backward force is due to the air resistance and the friction between the wheels and the track

In this case, Megan is travelling at constant speed. This means that her acceleration is zero:

a = 0

According to Newton's second law, the resultant of the forces acting on Megan is equal to the product between mass (m) and acceleration (a):

[tex]\sum F = ma[/tex]

However, a = 0, so the resultant of the forces is also zero:

[tex]\sum F =0[/tex]

and this implies that the forward force and the backward force are equal in magnitude and opposite in direction.

B) The forward force is larger than the backward force

In this case, Megan crouched down in order to make herself more streamlined. As a result, the air resistance acting on Megan will decrease: so, the backward force will decrease, and therefore the forward force (which has remained the same) will be larger than the backward force.

So, the resultant force

[tex]\sum F[/tex]

will be no longer zero, and therefore the acceleration will be different from zero, which means that Megan will increase her speed.

it is the vertical distance between the waterline and the bottom of hull and determines the minimum depth of water

Final answer:

In comparing isobaric, isothermal, and adiabatic processes for an expanding ideal gas, the isobaric process involves the greatest work done by the gas and the largest heat flow into the system, while the adiabatic process leads to a decrease in internal energy, indicating no heat flow into the gas.

Explanation:

An ideal gas expands through three different processes: isobaric, isothermal, and adiabatic, with its volume increasing to four times the original. Here's how each process impacts the work done, internal energy, and heat flow into the gas:

Isobaric (constant pressure): This process results in a significant work done by the gas and sees a large amount of heat flow into the gas due to the direct relationship between heat added and work done at constant pressure.

Isothermal (constant temperature): In this process, the internal energy of the gas does not change since any heat added to the system is entirely converted into work. Therefore, this process neither increases nor decreases the internal energy but can involve significant work done if heat is supplied.

Adiabatic (no heat exchange): This process results in a decrease in internal energy since the work done by the gas comes from its internal energy reservoir. No external heat is added to the system.

Answers to specific questions:

The work done by the gas is greatest during the isobaric process due to the direct relationship between pressure, volume, and work in this scenario.

The smallest amount of work done is a bit nuanced since all processes involve work, but the adiabatic process might be seen as involving 'less effective' work since it leads to a reduction in internal energy without heat intake.

The internal energy increases during isobaric expansion due to the heat flow into the gas.

The internal energy decreases during the adiabatic process as the gas does work on its surroundings at the expense of its internal energy.

The largest amount of heat flows into the gas during the isobaric process because work done on the gas directly translates to heat intake at constant pressure.

Physical sciences study nonliving matter, including fields like geology, astronomy, physics, and chemistry, with a focus on matter and energy interactions.

The term physical sciences pertains to the study of matter and energy. The field of physical science includes subjects like geology, astronomy, physics, and chemistry, which all explore various aspects of nonliving matter. Physics, being the most fundamental of these sciences, deals with concepts of energy, matter, space and time, and their interactions. It is essential for understanding the general truths of nature that are expressed through scientific laws and theories, which describe the rules that all natural processes appear to follow.

Answer:

The atomic number increases by 1.

Explanation:

The beta minus decay is a process in which a neutron decays into a proton, emitting an electron and an anti-neutrino:

[tex]n \rightarrow p + e + \bar{\nu}[/tex]

If this process occurs inside an unstable nucleus, we notice that:

- a neutron is converted into a proton, therefore

- the number of neutrons decreases by 1 and the number of protons increases by 1

Keep in mind that the atomic number of a nucleus corresponds to the number of protons it contains: therefore, since this number increases by 1, then the atomic number increases by 1.

Answer:

A. paths of the planets follow an elliptical orbit around the sun.

Explanation:

Nicolás Copernicus formulated the heliocentric theory of the solar system, where the Sun is the one in the center with the planets moving around it, contradicting what was believed for the time that it was that the Earth was in the center and both the Sun and the planets revolved around him (geocentrism).

This was the basis for Kepler finally describing the planetary movement based on 3 mathematical expressions. These expressions start by saying that the orbits were not circular, if not elliptical, so that the planets are governed by the Pythagorean laws of harmony. His studies showed that the distances of the planets to the Sun drew parallel spheres, being the first to draw the concentric orbits of the planets in their orbits around the Sun.

Kepler's laws are the following:

  - First law. The planets move in elliptical orbits, the sun being one of the foci.

  - Second law. The radius vector that joins the center of the Sun with the center of a planet describes equal areas in equal times.

  - Third law. The squares of the periods of the planets are proportional to the cubes of their distance from the Sun.

Answer:

D) Decreases by 4

Explanation:

The mass number of a nucleus is equal to the number of protons and neutrons in the nucleus:

A = p + n

where

p is the number of protons

n is the number of neutrons

An alpha particle is a nucleus of helium, consisting of 2 protons and 2 neutrons. This means that when an unstable nucleus emits an alpha particle, it loses 2 protons and 2 neutrons. Therefore, the new mass number of the nucleus will be

A' = (p-2) + (n-2) = p + n - 4 = A - 4

So, it will decrease by 4 units.

Answer:

4.5 V

Explanation:

The electric potential produced around a single point charge is:

[tex]V=k \frac{q}{r}[/tex]

where

k is the Coulomb's constant

q is the charge

r is the distance from the charge

We see that the electric potential is inversely proportional to the distance, r, so we can write:

[tex]V_1 r_1 = V_2 r_2[/tex]

where

V1 = 9 V

r1 = 1 m

V2 = ?

r2 = 2 m

Solving the equation, we find the voltage 2 m away from the charge:

[tex]V_2 = \frac{V_1 r_1}{r_2}=\frac{(9 V)(1 m)}{2 m}=4.5 V[/tex]

Final answer:

The voltage 2 m away from the charged object is 36 V.

Explanation:

The electric potential (voltage) at a distance of 1 m from the charged object is 9 V. To find the voltage at a distance of 2 m, we can use the inverse square law for electric potential:

V = kQ/r

Where V is the voltage, k is the electrostatic constant, Q is the charge, and r is the distance. Since the charge is unknown, we can use the ratio of the squares of the distances to find the voltage:

V₂/V₁ = (r₁/r₂)²

Substituting the given values, we have:

9/V₁ = (1/2)²

V₁ = 36 V

Therefore, the voltage 2 m away from the charge is 36 V.

Answer:

A metal sphere is neutral because it has an equal number of protons and electrons. Draw how the charges in the sphere are redistributed when a negatively charged rod is brought near it.

Answer:

two opposite charges: The force between them would be attractive. In the electric field the lines pointing outward from the positively charged particle would go toward the negatively charged particle  

two like charges: The force would repulse each other. In the electric field the lines would avoid each other.  

Explanation:

in the answer hope this helps!

Explanation:

In an isobaric process the pressure remains constant, which means the initial pressure and the final pressure will be the same.

In addition, during this thermodynamic process, the volume of the ideal gas expands or contracts in such a way that the variation of pressure [tex]\Delta P[/tex] is neutralized.

Now, according to the First law of Thermodynamics that establishes the conservation of energy:

[tex]\Delta U=\Delta Q-\Delta W[/tex]   (1)

Where:

[tex]\Delta U[/tex] is the internal energy

[tex]\Delta Q[/tex] is the heat transferred

[tex]\Delta W[/tex] is the work

Now, for an isobaric process:

[tex]\Delta W=P\Delta V[/tex]    (2)

Where:

[tex]P[/tex] is the pressure (always positive)

[tex]\Delta V[/tex] is the volume variation of the gas

Here we have two possible results:

-If the gas expands (positive [tex]\Delta V[/tex]), the work is positive.

-If the gas compresses (negative [tex]\Delta V[/tex]), the work is negative.

In this case we are talking about the first result (work is positive).

Then, according to the above, equation (1) can be written as follows:

[tex]\Delta U=\Delta Q - P\Delta V[/tex]   (3)

Clearing [tex]\Delta Q[/tex]:

[tex]\Delta Q=\Delta U+P \Delta V[/tex]    (4)

Then, for an ideal gas in an isobaric process, part of the heat ([tex]Q[/tex]) added to the system will be used to do work (positive in this case) and the other part will increase the internal energy, hence the temperature will increase as well.

Final answer:

In an isobaric expansion of an ideal gas, the gas does work and if heat is added, the temperature may increase, making options A, B, C, and E incorrect. The pressure remains constant by definition.

Explanation:

When a fixed amount of ideal gas goes through an isobaric expansion, it is essential to understand that the pressure remains constant by definition. In option A, if the process was isothermal, the internal energy would indeed not change since internal energy for an ideal gas is a function of temperature, but this isn't necessarily true for an isobaric process where temperature can change. Hence, option A is incorrect. Option B states the gas does no work, which is also incorrect; during an isobaric expansion, the gas does work as it expands against a constant external pressure. Option C would describe an adiabatic process, not an isobaric one, so this is incorrect in this context. Option D suggests that the temperature must increase, which could be true because when an ideal gas expands isobarically, heat is often added to keep the pressure constant, thereby increasing the temperature. Finally, option E states that the pressure must increase, which cannot happen in an isobaric process by definition.

Considering the context and mechanisms of thermodynamics, the correct answer is not explicitly stated among the choices but can be inferred. The most accurate answer regarding an isobaric expansion of an ideal gas would be that the gas does work and if heat is added to maintain constant pressure, the temperature is likely to increase.

Answer: Isotopes of an element will contain the same number of protons and electrons but will differ in the number of neutrons they contain. In other words, isotopes have the same atomic number because they are the same element but have a different atomic mass because they contain a different number of neutrons.

Answer:

15.1°

Explanation:

The horizontal velocity of the hockey puck is constant during the motion, since there are no forces acting along this direction:

[tex]v_x = 23.2 m/s[/tex]

Instead, the vertical velocity changes, due to the presence of the acceleration due to gravity:

[tex]v_y(t)= v_{y0} -gt[/tex] (1)

where

[tex]v_{y0}=0[/tex] is the initial vertical velocity

g = 9.8 m/s^2 is the gravitational acceleration

t is the time

Since the hockey puck falls from a height of h=2.00 m, the time it needs to reach the ground is given by

[tex]h=\frac{1}{2}gt^2\\t=\sqrt{\frac{2h}{g}}=\sqrt{\frac{2(2.00 m)}{9.8 m/s^2}}=0.64 s[/tex]

Substituting t into (1) we find the final vertical velocity

[tex]v_y = -(9.8 m/s^2)(0.64 s)=-6.3 m/s[/tex]

where the negative sign means that the velocity is downward.

Now that we have both components of the velocity, we can calculate the angle with respect to the horizontal:

[tex]tan \theta = \frac{|v_y|}{v_x}=\frac{6.3 m/s}{23.2 m/s}=0.272\\\theta = tan^{-1} (0.272)=15.1^{\circ}[/tex]

Final answer:

Using the kinematic equations for projectile motion, the final angle below the horizontal of the velocity of the puck just before it hits the ground is calculated to be 31.8° based on the given height of the fall and the initial horizontal velocity.

Explanation:

To find the angle below the horizontal of the velocity of the puck just before it hits the ground, we can use the kinematic equations for projectile motion. Considering that the puck experiences no air resistance, its horizontal velocity component remains constant at 23.2 m/s, and the vertical velocity component increases due to gravity (9.81 m/s2). First, we calculate the time it takes for the puck to fall 2.00 m using the vertical motion equation:

h = v0yt + (1/2)gt2

Since the puck slides off the table, the initial vertical velocity v0y is 0, so the equation simplifies to:

h = (1/2)gt2

Solving for t, we get:

t = sqrt((2h)/g)

Now that we have the time of fall, we can find the vertical velocity component just before impact using:

vy = gt

Finally, the angle θ can be calculated using the vertical and horizontal components:

tan(θ) = vy/vx

Plugging in the values:

θ = arctan(vy/vx)

After performing the calculations with the given numbers, we find that the angle is 31.8° below the horizontal just before the puck hits the ground. Therefore, the correct answer is 31.8°.

A.Ganerators

is the answer

Agree with previous answer.

A. Generators

Definitely B.

Unlike poles attract and like poles repeal

I'm not positive but if I'm reading the question right it would be the big bang sorry if I'm wrong

Answer:

Cape Point lighthouse

Explanation:

The lighthouse is located South of Cape Town, at a point where boats turn to go around the tip of Africa.

The new lighthouse has the most powerful light of all the lighthouses in South Africa, with a power of 10 megacandelas.  That's why it's being visible for up to 63 km around.

It's a very important lighthouse helping to conduct the traffic around dangerous waters where 2 oceans meet.

Answer : The correct option is, (C) 45 degrees Celsius.

Explanation :

Endothermic reaction : It is defined as the chemical reaction in which the energy is absorbed from the surrounding.

In the endothermic reaction, the energy of reactant are less than the energy of product.  During endothermic reaction, initially the temperature of the reaction is high because initially amount of heat is given to the system and after the reaction, the temperature of the reaction is low.

Exothermic reaction : It is defined as the chemical reaction in which the energy is released into the surrounding.

In the exothermic reaction, the energy of reactant are more than the energy of product. During exothermic reaction, initially the temperature of the reaction is low because initially there is no heat is given to the system and after the reaction, the temperature of the reaction is high because after ther reaction, more amount of energy is released.

As per question, a student performs an exothermic reaction in a beaker and measures the temperature. Initially, the thermometer reads 35 degrees Celsius. After the reaction, the thermometer temperature will be more that initial temperature that is, 45 degrees Celsius.

Hence, correct option is, (C) 45 degrees Celsius.

*The product of photosynthesis is B) glucose because it makes glucose from the plant.

The products of photosynthesis are Glucose, Oxygen and water. Since oxygen and water exit through stomata, the main product is Glucose.

Answer: Option B

Explanation:

The solar energy is utilized to produce sugar in the process of photosynthesis. This process occurs in plants, bacteria's and protistans. In the photosynthesis process, the sunlight energy is transformed into some usable chemical energy. It is possible due to the pigment called chlorophyll which is green in color and present in plants.  

Most time photosynthesis process makes use of water and releases oxygen as output. The leaves of the plants are the collector of solar. The intakes of photosynthesis process are carbon dioxide, water and the results are glucose and oxygen.  

Answer: the air makes it go WHOOSH!!

Explanation:

just kidding. the air pushes the wings up because of the way they are shaped. this creates lift.

When all of these things work together(mentioned below), the big heavy piece of metal becomes a plane that can fly high up in the sky!

Aeronautics is the science of designing planes and other flying machines. Aeronautical engineers must understand four fundamental areas in order to design planes. Engineers must understand all of these elements in order to design a plane.

A plane uses something called "air pushing it up" to help it fly. This air pushing is called "lift." The wings of the plane are shaped like long, flat feathers that help create lift.

Another way the plane flies is by using its engine to make a strong "whoosh" of air that moves the plane forward. This strong "whoosh" of air is called "thrust."

And finally, the plane uses its tail to help it steer and balance, just like a bird uses its tail to help it fly straight.

So, when all of these things work together, the big heavy piece of metal becomes a plane that can fly high up in the sky.

Learn more about aeronautics here:
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Density [tex]D[/tex]  is a characteristic property of a substance, material or object and is defined as the relationship between the mass and volume of that specific substance or material.

This is due the fact that any object or material has mass and volume, however the mass of different substances occupy different volumes.  As shown in the following equation:

[tex]D=\frac{m}{V}[/tex]

Where:

[tex]m[/tex] is the mass of the object

[tex]V[/tex] is the volume of the object

This is why changing the shape of an object not affect its density.

Final answer:

The density of an object, being mass per unit volume, does not change when its shape is altered because both the object's mass and volume remain consistent, keeping density constant. This property is intrinsic to the material, and unrelated to shape or thermal conductivity. Only changes in temperature can affect the density by affecting the volume while keeping the mass constant.

Explanation:

Changing the shape of an object does not affect its density because density is defined as the mass per unit volume. This property, how much mass there is in one unit of volume, is an intrinsic characteristic of a material and does not depend on the object's shape. When you change the shape of an object, you do not change its mass or the amount of space it occupies, hence the density remains constant.

Even when an object undergoes a shape transformation, like clay being molded from a lump into a boat, its mass and volume stay the same which keeps the density unchanged. However, this transformation can affect the object's ability to float or sink due to the principle of displacement as stated in Archimedes' Principle. A lump of clay sinks because it displaces less water, whereas the same lump shaped like a boat displaces more water and can float.

It's also important to understand that while volumes and densities can change with temperature changes, the mass remains constant with temperature. According to the US Department of the Interior, the true density of water depends on its temperature, emphasizing the influence of temperature on density rather than shape.

Answer:

4

Explanation:

In order for the current to continue flowing through the circuit (and for the bulbs to continue shining), there must be a closed path containing the battery where current can flow. Let's see the effect of removing each bulb on the circuit:

- 1: when removing bulb 1 only, the current can still flow through the path battery-bulb 3- bulb 4

- 2: when removing bulb 2 only, the current can still flow through the path battery-bulb 3- bulb 4

- 3: when removing bulb 3 only, the current can still flow through the path battery-bulb 1-bulb 2- bulb 4

- 4: when removing bulb 4 only, the current can no longer flow. In fact, there is no closed path that contains the battery now, so the current will not flow and all the bulbs will stop shining.

Answer:

4

Explanation:

It is a parrallel circuit

Answer:

120.0v drop across the 20.0 resistor

Explanation:

Answer:

C. one magnet with a north pole and a south pole

Explanation:

If we approximate the orbit of the planets around the Sun to circular orbits with a uniform circular motion, where the velocity [tex]\vec{V}[/tex] is a vector, whose direction is perpendicular to the radius [tex]r[/tex] of the trajectory; the acceleration [tex]\vec{a}[/tex] is directed towards the center of the circumference (that's why it's called centripetal acceleration).  

Now, according to Newton's 2nd law, the force [tex]\vec{F}[/tex] is directly proportional and in the same direction as the acceleration:  

[tex]\vec{F}=m.\vec{a}[/tex]  

Therefore the net force resulting from the movement of a planet orbiting the Sun points towards the center of the circle, this is called Centripetal Force which is a central force that in this case is equal to the gravity force.

Hi

The total displacement is 2 m south

I hope this helps

Answer:

2 m south

Explanation:

Displacement is measure of change in the position of an object. It is a vector quantity, that is, it has both magnitude and direction.

When the child walked 4 m south, its displacement is 4 m south.

Then it moved 2 m back opposing direction to the north. The resultant displacement is 4 - 2 = 2 m south.

Then it moved 5 m south, same direction, displacement becomes 2 + 5 = 7 m south.

And finally, it moved 5 m north, opposing direction. 7 - 5 = 2 m south.

The final displacement of the child is 2 m south.

Answer:

a few hundred thousand years after the Big Bang

Explanation:

Answer:

C

Explanation:

Radiation affects both cancer cells and healthy cells, but it affects cancer cells more.

Radiation is often used in cancer treatment because the rapid cell division of cancer cells makes them vulnerable to radiation damage. These cells often cannot repair this damage as effectively as healthy cells, leading to their destruction. However, radiation is not the only method for fighting cancer.

Radiation is often used to destroy cancer cells because, in general, cancer cells divide more rapidly than normal cells, which makes them more susceptible to the damaging effects of radiation. This is the reason behind the option (C). While radiation does affect both cancerous and healthy cells, the quick division of cancer cells often makes them more vulnerable to being damaged by the radiation. However, they often cannot repair this damage as effectively as healthy cells can. Consequently, the cancer cells are destroyed, with minimal effect on the healthy cells. It's important to note that radiation is not the only method to fight cancer as stated in option (D). Other methods include surgery, chemotherapy, and immunotherapy. Furthermore, radiation is not a tracer that picks out cancer cells to destroy as stated in option (B).

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Answer:

B

Explanation:

Energy at the top of the hill = energy at the bottom of the hill + energy lost

PE = KE + E

mgh = 1/2 mv² + E

(52 kg) (9.8 m/s²) (50.0 m) = 1/2 (52 kg) (25 m/s)² + E

25480 J = 16250 J + E

E = 9230 J

Answer:

A

Explanation:

Nasty, but doable.

I = 2 amps

R = 8 ohms

V = I * R

V = 2 * 8

V = 16 volts.

========

The 4 ohm resistor sees the same voltage -- 16 volts.

V = 16

R = 4ohms

I = V/R

I = 16/4

I = 4 amps.

The current seen by the unknown resistor R is

It = 4 amps + 2 amps

It = 6 amps

Answer A.

Answer:

Force increases nine times its initial value

Explanation:

For charges, charged bodies very small compared to the distance [tex]r[/tex] that separates them, Coulomb discovered that the electric force is proportional to [tex]\frac{1}{r^{2}}[/tex]

So, if the distance is made a third of what it was, the force will be increased nine times its initial value