Question 1

Which of the following statements best describes Newton's First Law of Motion?

Accepted Answer

An object will remain at rest or move with constant velocity unless acted upon by a net external force.

Question 2

A 10 kg box rests on a horizontal surface. If the coefficient of static friction between the box and the surface is 0.4, what is the minimum horizontal force required to start moving the box? (Assume $$g = 9.8\ \mathrm{m/s^2$})$$

Accepted Answer

$$39.2\ \mathrm{N}$$

Question 3

Which of the following is NOT a contact force?

Accepted Answer

Weight

Question 4

A 5 kg object is acted on by two forces: $$\vec{F}_1 = 10\ \mathrm{N}$$ east and $$\vec{F}_2 = 6\ \mathrm{N}$$ north. What is the magnitude of the object's acceleration?

Accepted Answer

$$2.0\ \mathrm{m/s^2$}$$

Question 5

A car of mass $$1000\ \mathrm{kg} is $$moving in a circle of radius $$50\ \mathrm{m} at a $$constant speed of $$10\ \mathrm{m/s}. $$What is the magnitude of the net force acting on the car?

Accepted Answer

$$2000\ \mathrm{N}$$

Question 6

Which of the following best explains why astronauts feel 'weightless' while orbiting Earth?

Accepted Answer

They are in free fall, with gravity as the only force acting on them.

Question 7

A person pushes a box across a floor at constant velocity. Which statement is true about the forces acting on the box?

Accepted Answer

The net force on the box is zero.

Question 8

A 2 kg object is hanging from a rope. What is the tension in the rope if the object is at rest? (Assume $$g = 9.8\ \mathrm{m/s^2$})$$

Accepted Answer

$$19.6\ \mathrm{N}$$

Question 9

Which of the following is a correct statement of Newton's Third Law?

Accepted Answer

For every action, there is an equal and opposite reaction.

Question 10

A 20 N force is applied at an angle of $$30^\circ$$ above the horizontal to a box on a frictionless surface. What is the horizontal component of the force?

Accepted Answer

$$17.3\ \mathrm{N}$$

Question 11

A 50 kg student stands on a scale in an elevator. If the elevator accelerates upward at $$2\ \mathrm{m/s^2$}$$, what does the scale read? (Assume $$g = 9.8\ \mathrm{m/s^2$})$$

Accepted Answer

$$590\ \mathrm{N}$$

Question 12

Which of the following is the correct SI unit for force?

Accepted Answer

Newton

Question 13

A block is at rest on an inclined plane. Which force is responsible for preventing the block from sliding down?

Accepted Answer

Friction force

Question 14

A 3 kg object is acted on by a net force of $$12\ \mathrm{N}. $$What is its acceleration?

Accepted Answer

$$4\ \mathrm{m/s^2$}$$

Question 15

A person is standing in a bus that suddenly accelerates forward. Why does the person appear to fall backward?

Accepted Answer

The person's inertia resists the change in motion.

Question 16

If the net force on an object is zero, which of the following must be true?

Accepted Answer

The object moves with constant velocity or remains at rest.

Question 17

A 4 kg block is pulled by a horizontal force of $$20\ \mathrm{N}$$ across a frictionless surface. What is the acceleration of the block?

Accepted Answer

$$5\ \mathrm{m/s^2$}$$

Question 18

Which of the following best describes the normal force?

Accepted Answer

A force exerted by a surface perpendicular to the object in contact with it.

Question 19

A 10 kg box is suspended by a rope. If another 10 kg box is attached to the first, what is the total tension in the rope? (Assume $$g = 9.8\ \mathrm{m/s^2$})$$

Accepted Answer

$$196\ \mathrm{N}$$

Newton’s Laws of Motion: Structured Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards