Question 1

A car travels 10 km east from point A to point B, then 10 km west back to point A in a total time of 30 minutes. What is the car's average velocity for the entire trip?

Accepted Answer

$$0\ \mathrm{km/min}$$

Question 2

Which of the following statements correctly distinguishes between a scalar and a vector quantity?

Accepted Answer

A vector has magnitude and direction, while a scalar has only magnitude.

Question 3

A train moves along a straight track. Its position-versus-time graph is a straight line with a positive slope. What does this indicate about the train's motion?

Accepted Answer

The train is moving at a constant velocity in the positive direction.

Question 4

Given the position function $$x(t) = 2.0\ \mathrm{m} + 0.5\ \mathrm{m/s} \cdot t$$, what is the instantaneous velocity of the object at any time $$t$$?

Accepted Answer

$$0.5\ \mathrm{m/s}$$

Question 5

A helicopter flies east a distance $$d at $$speed $$v$$, then immediately turns and flies west a distance $$2d at $$speed $$1.5v. $$What is the x component of the helicopter's average velocity for the entire trip? (Assume east is positive x direction.)

Accepted Answer

$$-\dfrac{d}{d/v + 2d/(1.5v)}$$

Question 6

Which feature of a position-versus-time graph indicates that an object is moving at constant velocity?

Accepted Answer

The graph is a straight line with nonzero slope.

Question 7

A runner travels 5 km north in 30 minutes, then 5 km south in 20 minutes. What is the runner's average speed for the entire trip?

Accepted Answer

$$\dfrac{10\ \mathrm{km}}{50\ \mathrm{min}} = 0.20\ \mathrm{km/min}$$

Question 8

If the position of a particle is given by $$x(t) = 0.12\ \mathrm{m/s^2$} \cdot t^2$, what is the x component of the particle's instantaneous velocity at t = 1.0$$\ \mathrm{s}$$?

Accepted Answer

$$0.36\ \mathrm{m/s}$$

Question 9

Which of the following is true about the area under a velocity-versus-time graph for an object moving in one dimension?

Accepted Answer

It represents the object's displacement.

Question 10

A cyclist rides from $$x = 2.0\ \mathrm{m} to$$ $$x = 3.5\ \mathrm{m} at a $$constant speed of $$0.6\ \mathrm{m/s}. $$How long does the trip take?

Accepted Answer

$$1.5\ \mathrm{s}$$

Question 11

Which of the following best describes the relationship between average speed and average velocity for a round-trip journey?

Accepted Answer

Average velocity is always zero.

Question 12

An object moves from $$x_i = -1.2\ \mathrm{m} to$$ $$x_f = -2.3\ \mathrm{m}$$ without reversing direction. What is the sign of the x component of its average velocity?

Accepted Answer

Negative

Question 13

Which mathematical operation gives the instantaneous velocity from a position-versus-time function $$x(t)$$?

Accepted Answer

Taking the derivative of $$x(t)$$ with respect to time

Question 14

A position-versus-time graph for an object shows a curve that is steeper at earlier times and flattens out at later times. What does this indicate about the object's motion?

Accepted Answer

The object is slowing down.

Question 15

If a position-versus-time graph shows two different positions for the same time, what does this imply about the motion?

Accepted Answer

The motion is impossible.

Question 16

A car travels 10 km at 10 km/h, then another 10 km at 20 km/h. What is the car's average speed for the entire 20 km trip?

Accepted Answer

$$13\ \mathrm{km/h}$$

Question 17

Which of the following is the correct vector notation for a velocity vector pointing in the x direction with magnitude $$v_x$$?

Accepted Answer

$$v_x \hat{x}$$

Question 18

A ball's position is given by $$x(t) = 3.0\ \mathrm{m} + 2.0\ \mathrm{m/s} \cdot t. $$What is its displacement after 4 seconds?

Accepted Answer

$$11.0\ \mathrm{m}$$

Question 19

Which of the following statements about vectors is correct?

Accepted Answer

To subtract one vector from another, reverse the direction of the vector being subtracted and add.

Chapter 2: Motion in One Dimension – Principles & Practice of Physics (Masur)

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