Question

force ok - 12 practice questions

1. force is a push or pull acting on an object.

a. true b. false

1. the force required to change an objects motion depends on the objects mass.

a. true b. false

1. what is not a force that controls the motion of everyday objects?

a. gravity b. friction c. applied force d. acceleration

1. fill in the blank(s): force is a vector because it has both magnitude and direction
2. select all possible answers: which of the following are the main forces that affect the motion of everyday object

a. applied force b. gravity c. friction d. mass

1. force is a vector.

a. true b. false

1. which of the following is not a fundamental force of the universe?

a. gravity b. nuclear c. electromagnetic d. mass

1. only some changes in speed or direction are caused by forces.

a. true b. false

1. what is the si unit for force? answer: newton
2. mass refers to the gravitational force on matter in contact with the surface of a planet.

a. true b. false

Explanation:

Step1: Recall force definition

Force is a push or pull acting on an object, so 1. is a. TRUE

Step2: Recall Newton's second - law

The force required to change an object's motion depends on mass ($F = ma$), so 2. is a. TRUE

Step3: Distinguish force and motion - related concepts

Acceleration is not a force but a result of force according to $F=ma$. Gravity, friction and applied force are forces. So 3. is d. acceleration

Step4: Recall vector properties

Force is a vector as it has magnitude and direction, so 4. is "direction"

Step5: Identify forces affecting motion

Applied force, gravity and friction are forces affecting motion, mass is not a force. So 5. is a. applied force, b. gravity, c. friction

Step6: Recall vector nature of force

Force is a vector, so 6. is a. TRUE

Step7: Recall fundamental forces

Gravity, nuclear and electromagnetic are fundamental forces, mass is not a force. So 7. is d. mass

Step8: Recall Newton's first - law

Any change in speed or direction (acceleration) is caused by a force. So 8. is b. FALSE

Step9: Recall SI unit of force

The SI unit of force is Newton, so 9. is Newton

Step10: Distinguish mass and weight

Mass is the amount of matter, weight is the gravitational force on matter. So 10. is b. FALSE

Answer:

1. a. TRUE
2. a. TRUE
3. d. acceleration
4. direction
5. a. applied force, b. gravity, c. friction
6. a. TRUE
7. d. mass
8. b. FALSE
9. Newton
10. b. FALSE