Question 1

Which of the following statements best describes the concept of force in physics?

Accepted Answer

A force is a vector quantity that represents a push or pull resulting from an interaction between two objects or between an object and its environment.

Question 2

A box rests on a horizontal surface. Which force acts perpendicular to the surface and is responsible for supporting the box against gravity?

Accepted Answer

Normal force $$\vec{n}$$

Question 3

A hockey puck slides across frictionless ice. If no net external force acts on the puck, what will happen to its motion according to Newton's first law?

Accepted Answer

It will continue moving in a straight line at constant speed.

Question 4

Which of the following is NOT a contact force?

Accepted Answer

Weight $$\vec{w}$$

Question 5

A person stands on a scale in an elevator that is accelerating upward with acceleration $$a. $$What is the reading on the scale?

Accepted Answer

$$m(g+a)$$

Question 6

A car is moving at constant velocity on a straight road. Which statement is true about the net force acting on the car?

Accepted Answer

The net force is zero.

Question 7

A block of mass $$m is $$pulled across a horizontal surface by a rope with tension $$T. If $$the block moves at constant velocity, what is the relationship between the tension and the friction force $$f$$?

Accepted Answer

$$T = f$$

Question 8

A 5 kg object is subjected to a net force of 20 N. What is its acceleration?

Accepted Answer

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

Question 9

If the net force acting on an object is doubled, what happens to its acceleration, assuming mass remains constant?

Accepted Answer

The acceleration is doubled.

Question 10

A 10 kg object is on Earth, where $$g = 9.8\ \mathrm{m/s^2$}. $$What is the weight of the object?

Accepted Answer

$$98\ \mathrm{N}$$

Question 11

A person pushes backward on the ground while walking. According to Newton's third law, what force propels the person forward?

Accepted Answer

The ground pushes forward on the person with a force equal in magnitude and opposite in direction to the push.

Question 12

Two blocks, one of mass $$m_1$$ and the other of mass $$m_2$$, are fastened together and pulled by a force $$F. $$What is the acceleration of the system?

Accepted Answer

$$a = \dfrac{F}{m_1$ + m_2$}$$

Question 13

A car crash test dummy continues moving forward when the car suddenly stops. This is best explained by:

Accepted Answer

Newton's first law of motion.

Question 14

Which of the following is an inertial frame of reference?

Accepted Answer

A laboratory fixed to the Earth (ignoring Earth's rotation and revolution).

Question 15

A block is sliding down an inclined plane at constant velocity. Which statement is true about the forces acting on the block?

Accepted Answer

The friction force is equal in magnitude and opposite in direction to the component of gravity down the incline.

Question 16

A ball of mass $$m is $$attached to a string and swung in a horizontal circle of radius $$r at $$constant speed $$v. $$What is the magnitude of the net force acting on the ball?

Accepted Answer

$$F = \dfrac{m v^2$}{r}$$

Question 17

Which of the following best describes the relationship between mass and weight?

Accepted Answer

Weight is the gravitational force on an object and is given by $$w = m g.$$

Question 18

A block is pulled by a rope with tension $$T at an $$angle $$	heta$$ above the horizontal. What is the horizontal component of the tension?

Accepted Answer

$$T \cos 	heta$$

Question 19

A 2 kg object and a 3 kg object are connected and pulled by a net force of 10 N. What is the acceleration of the system?

Accepted Answer

$$a = 2\ \mathrm{m/s^2$}$$

Question 20

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

Accepted Answer

N

Chapter 04

Guida di studio - Domande di pratica

Study guide - Flashcard