Question 1:

Newton's Third Law of Motion states that for every action, there is an equal and opposite reaction. This means that when one object exerts a force on a second object, the second object simultaneously exerts a force on the first object that is equal in magnitude and opposite in direction. These forces always occur in pairs.

For example, when a rocket launches, it exerts a downward force on the hot exhaust gases (the "action"). In reaction, the gases exert an equal and opposite upward force on the rocket (the "reaction"), which is what propels it upwards.

The correct answer is C. Newton's Third Law.

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
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Question 2:

Newton's First Law of Motion, also known as the Law of Inertia, states that an object at rest will remain at rest, and an object in motion will remain in motion with the same speed and in the same direction unless acted upon by an unbalanced force. A constant velocity means both a constant speed and a constant direction. This law fundamentally describes the inherent tendency of objects to resist a change in their state of motion.

For example, a puck sliding on a frictionless surface in space will continue to move forever in a straight line at a constant velocity because there are no external forces (like friction or air resistance) to stop it. On Earth, however, objects slow down because of these resistive forces.

The correct answer is A. Newton's First Law.

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 3:

When an object is moving in a straight line at a constant velocity with no net force acting on it, its acceleration is zero. This state is known as translational equilibrium.

Here's why:

Translational Motion: This refers to the movement of an object from one point to another without any rotation.

Equilibrium: In physics, equilibrium means the net force acting on an object is zero. This can be the case for an object at rest (static equilibrium) or for an object moving with a constant velocity (dynamic equilibrium).

The state of an object at a constant velocity is a direct result of Newton's First Law of Motion, which states that an object's velocity will not change unless a net external force acts upon it.

The correct answer is B. translational equilibrium.

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 4:

The correct answer is A. The force from a gun on a bullet, and the force causing the recoil of the gun.

Newton's Third Law Pairs
According to Newton's Third Law, forces always occur in pairs. These pairs are often called "action-reaction" pairs. To be a true Newton's third law pair, the two forces must meet four specific criteria:

• They must be equal in magnitude.
• They must be opposite in direction.
• They must be of the same type of force (e.g., both gravitational forces, or both contact forces).
• They must act on different objects.

Let's apply these rules to the given options:

A. The force from a gun on a bullet, and the force causing the recoil of the gun.

The gun (Object A) exerts a force on the bullet (Object B) to accelerate it forward.

The bullet (Object B) simultaneously exerts an equal and opposite force on the gun (Object A), causing it to recoil.

The forces are equal, opposite, of the same type (contact/propulsion), and act on different objects. This is a perfect example of a Newton's third law pair.

B. The force from a car's engine pushing it down a road, and the air resistance acting against the motion.

These two forces act on the same object (the car).

One is a driving force, and the other is a resistive force. They are not a third law pair. They can be equal in magnitude and opposite in direction if the car is moving at a constant velocity, but they are not the result of a single, mutual interaction between two objects.

C. The force from the Sun on the Earth, and the centripetal force pulling round in an orbit.

The force from the Sun on the Earth is the gravitational force.

The centripetal force is not a separate force; it is the net force that is causing the circular motion. In the case of the Earth orbiting the Sun, the gravitational force from the Sun is the centripetal force. These are two descriptions of the same force, not a pair of forces acting on two different objects.

D. The force produced by wind on a boat's sails, and the force of friction of the water on the boat.

Similar to option B, these two forces act on the same object (the boat).

They are not a Newton's third law pair because they are not an action-reaction pair from a single interaction.

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 5:

There are two distinct Newton's third law pairs in this situation, both of which are action-reaction pairs. Remember, for a pair of forces to be a Newton's third law pair, they must be equal in magnitude, opposite in direction, be of the same type of force, and act on different objects.

Here is a breakdown of the two pairs:

First Newton's Third Law Pair
W: The weight of the block. This is the force of gravity of the Earth pulling the block downwards.

Z: The force of gravity of the block on the Earth. This is the force of gravity of the block pulling the Earth upwards.

These two forces fit all the criteria:

• They are equal in magnitude.
• They are opposite in direction (W is down, Z is up).
• They are both of the same type of force (gravitational force).
• They act on different objects (W acts on the block, Z acts on the Earth).

Second Newton's Third Law Pair
R: The reaction of the ground on the block. This is the contact force of the ground pushing the block upwards.

Y: The force of the block pushing the ground downwards. This is the contact force of the block pushing the ground downwards.

These two forces also fit all the criteria:

• They are equal in magnitude.
• They are opposite in direction (R is up, Y is down).
• They are both of the same type of force (contact force).
• They act on different objects (R acts on the block, Y acts on the ground).

W and R are not a third law pair because they both act on the same object (the block), are different types of force (gravitational and contact), and are only equal in magnitude because the block is in equilibrium.

The correct answer is A. W and Z, and R and Y.

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 6:

The rate of change of momentum is equal to the net force applied to an object. This is a statement of Newton's Second Law of Motion in its original and most general form.

The correct answer is D. Force.

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 7:

This is the most common form of Newton's Second Law and applies to objects with a constant mass. It's derived from the more general form of the law, which states that force is the rate of change of momentum
(F= Δp/Δt)

Momentum (p) is defined as mass (m) times velocity (v), so p=mv.

Therefore, the change in momentum is Δp=Δ(mv).

If the mass (m) is constant, it doesn't change, so we can take it out of the change function: Δp=mΔv.

Substituting this back into the original equation: F= mΔv / Δt

Since acceleration (a) is defined as the rate of change of velocity, a= Δv / Δt, we can substitute this in to get the final, simplified equation:
F=ma

The correct answer is A. F = ma.

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 8:

Acceleration is the change in velocity over time.
a= (final velocity−initial velocity) / time
a =(17 m/s−2 m/s) / 20 s
a = 15/20
a =0.75 m/s ²

This corresponds to answer D.

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 9:

Change in momentum
The change in momentum (Δp) is the mass of the object multiplied by its change in velocity.
Δp=m×Δv
Δp=5000 kg×(17 m/s−2 m/s)
Δp=5000 kg×15 m/s=75000 kg m/s

This corresponds to answer D

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 10:

Force provided by the engine
According to Newton's Second Law, force is the rate of change of momentum.
F=Δp/ Δt
F= 75000 kg ms^-1 / 20 s
=3750 N

To convert this to kilonewtons (kN), you divide by 1000.
F= 3.75 kN

This corresponds to answer C

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.