Lesson 11 & 12: Newton's Laws of Motion

Question 1

Question 1:
What does Newton’s 1st Law of Motion state?

A) An object in motion will accelerate if a net force acts on it.
B) An object at rest will remain at rest unless acted upon by a net force.
C) For every action, there is an equal and opposite reaction.
D) The acceleration of an object is directly proportional to the net force acting on it.

Answer 1

B) An object at rest will remain at rest unless acted upon by a net force.

Question 2

Question 2:
What is the formula associated with Newton’s 2nd Law of Motion?

A) F = ma
B) F = mv
C) F = m/g
D) F = 0

Answer 2

A) F = ma

Question 3

Question 3:
According to Newton’s 3rd Law of Motion, if object A exerts a force on object B, what occurs?

A) Object B exerts a greater force on object A.
B) Object B exerts an equal and opposite force on object A.
C) Object A experiences no change.
D) Object B exerts no force at all.

Answer 3

Answer: B) Object B exerts an equal an

Question 4

Question 4:
What does “net force” refer to?
A) The total force acting on an object when balanced.
B) The unbalanced force resulting from the combination of all forces acting on an object.
C) The force exerted by an object at rest.
D) The force required to keep an object in motion.

Answer 4

B) The unbalanced force resulting from the combination of all forces acting on an object.

Question 5

Question 5:
What is depicted in a free-body diagram (FBD)?
A) Only the mass of an object.
B) The speed of an object.
C) The relative magnitude and direction of all forces acting on an object.
D) The path of an object in motion.

Answer 5

C) The relative magnitude and direction of all forces acting on an object.

Question 6

Question 6:
Which of the following statements about action-reaction pairs is true? A) They cancel each other out because they are equal and opposite.
B) They act on the same object.
C) They do not cancel each other because they act on different objects.
D) They can exist in isolation.

Answer 6

C) They do not cancel each other because they act on different objects.

Question 7

What is another name for Newton’s 1st Law of Motion?
A) Law of Acceleration
B) Law of Action-Reaction
C) Law of Inertia
D) Law of Force

Answer 7

C) Law of Inertia

Question 8

Question 8:
According to the 2nd Law of Motion, if the mass of an object is constant and the net force increases, what happens to the acceleration?
A) It decreases.
B) It remains the same.
C) It increases.
D) It becomes zero.

Answer 8

C) It increases.

Question 9

Question 9:
In the context of Newton’s 2nd Law, which of the following scenarios demonstrates a constant net force? A) An object in free fall without air resistance.
B) A car accelerating from rest.
C) A stationary object.
D) A ball rolling on a frictionless surface.

Answer 9

A) An object in free fall without air resistance.

Question 10

Question 10:
What must be true for an object to remain in motion at a constant velocity according to Newton’s 1st Law?
A) There must be a net force acting on it.
B) The net force must be zero.
C) The object must be in a vacuum.
D) The object’s mass must increase.

Answer 10

B) The net force must be zero.

Question 11

Question 11:
Which of the following is NOT a rule for constructing a free-body diagram (FBD)?
A) Represent the object by a box.
B) Include all forces acting on the object.
C) Draw force vectors toward the center of the box.
D) Show the direction of each force accurately.

Answer 11

C) Draw force vectors toward the center of the box.

Question 12

Question 12:
What happens when two objects interact, according to Newton’s 3rd Law of Motion?
A) The object with greater mass exerts more force.
B) Both objects exert forces of equal magnitude and opposite direction.
C) One object will always move and the other will not.
D) Forces are always canceled out.

Answer 12

B) Both objects exert forces of equal magnitude and opposite direction.

Question 13

Question 13:
What is an implication of Newton’s 2nd Law when the net force is constant?
A) The greater the net force, the smaller the acceleration.
B) The acceleration remains constant regardless of mass.
C) The greater the mass, the smaller the acceleration.
D) The mass has no effect on acceleration.

Answer 13

C) The greater the mass, the smaller the acceleration.

Question 14

Question 14:
Which statement best describes the relationship between force and motion according to Newton’s Laws? A) A force is only needed to start motion.
B) A net force can change an object’s state of motion.
C) Forces do not affect stationary objects.
D) An object in motion will eventually stop without any forces acting on it.

Answer 14

B) A net force can change an object’s state of motion.

Question 15

Question 15:
What is meant by “no isolated force” in the context of Newton’s 3rd Law? A) Forces can act independently of each other.
B) Every force occurs as part of an interaction with another force.
C) Forces always require a mass to act upon.
D) Forces can exist without a corresponding reaction.

Answer 15

B) Every force occurs as part of an interaction with another force.

Question 16

Question 16:
A hockey puck slides across a smooth ice surface at a constant speed. According to Newton’s 1st Law of Motion, which statement is true?
A) A net force is acting on the puck to maintain its speed.
B) The puck will eventually stop due to friction.
C) The puck will continue to move at constant velocity until acted upon by a net force.
D) The puck will speed up because it is in motion.

Answer 16

C) The puck will continue to move at constant velocity until acted upon by a net force.

Question 17

Question 17:
A car accelerates from a stop to 60 km/h in 5 seconds. If the mass of the car is 800 kg, what is the net force acting on it?
A) 160 N
B) 240 N
C) 3200 N
D) 4800 N

Answer 17

C) 3200 N
(Using F = ma; acceleration = (60 km/h to m/s) / 5 s = 3.33 m/s², so F = 800 kg × 4 m/s² = 3200 N)

Question 18

Question 18:
A person pushes against a wall with a force of 50 N. According to Newton’s 3rd Law, what is the reaction force?
A) The wall pushes back with a force of 50 N.
B) There is no reaction force.
C) The wall pushes back with a force greater than 50 N.
D) The wall pulls the person with a force of 50 N.

Answer 18

A) The wall pushes back with a force of 50 N.

Question 19

Question 19:
An astronaut in space throws a heavy tool away from him. What happens to the astronaut?
A) He moves toward the tool.
B) He remains stationary.
C) He moves in the opposite direction of the tool.
D) He accelerates more than the tool.

Answer 19

C) He moves in the opposite direction of the tool.
(This demonstrates action-reaction pairs from Newton’s 3rd Law.)

Question 20

Question 20:
A ball is dropped from a height and accelerates downwards. If air resistance is negligible, what can be said about the forces acting on the ball?
A) The net force is zero.
B) The only force acting on it is gravity.
C) The ball is experiencing an upward force.
D) The ball will stop accelerating after a certain height.

Answer 20

B) The only force acting on it is gravity.

Question 21

Question 21:
A skateboarder pushes off the ground with their foot to accelerate forward. Which law of motion does this scenario illustrate?
A) 1st Law
B) 2nd Law
C) 3rd Law
D) None of the above

Answer 21

C) 3rd Law
(The foot exerts a force on the ground, and the ground exerts an equal and opposite force that propels the skateboarder forward.)

Question 22

Question 22:
A car travels at a constant speed of 80 km/h on a flat road. What can be inferred about the forces acting on the car?
A) There is a net force acting on the car.
B) The driving force is greater than the frictional force.
C) The driving force is equal to the frictional force.
D) The car is experiencing acceleration.

Answer 22

C) The driving force is equal to the frictional force.