Question 1

Which of the following statements best distinguishes a vector quantity from a scalar quantity?

Accepted Answer

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

Question 2

A car travels 60 km east, then 80 km west. What is the car's displacement and total distance traveled?

Accepted Answer

Displacement: $$-20\ \mathrm{km}$$, Distance: $$140\ \mathrm{km}$$

Question 3

Which of the following is the correct mathematical expression for average velocity?

Accepted Answer

$$v_{\mathrm{ave}} = \frac{x_2$ - x_1$}{t_2$ - t_1$}$$

Question 4

A runner completes a 400 m lap in 50 s, ending at the starting point. What is the runner's average velocity and average speed?

Accepted Answer

Average velocity: $$0\ \mathrm{m/s}$$, Average speed: $$8.0\ \mathrm{m/s}$$

Question 5

An object moves with a constant acceleration of $$-4.0\ \mathrm{m/s^2$}. At$$ $$t=2.0\ \mathrm{s}$$, its velocity is $$+10.0\ \mathrm{m/s}. $$What was its velocity at $$t=0.0\ \mathrm{s}$$?

Accepted Answer

$$v_0 = +18.0$$\ \mathrm{m/s}$$

Question 6

A ball is thrown straight upward with an initial velocity of $$32\ \mathrm{m/s}. $$Ignoring air resistance, how long does it take to reach its maximum height?

Accepted Answer

$$t = 3.26\ \mathrm{s}$$

Question 7

Which of the following best describes the acceleration of an object in free fall near Earth's surface (ignoring air resistance)?

Accepted Answer

It is constant and equal to $$-9.81\ \mathrm{m/s^2$}$$, regardless of the object's mass.

Question 8

A car is moving at $$+24.5\ \mathrm{m/s}$$ and the driver sees an obstacle. The driver's reaction time is $$0.70\ \mathrm{s}$$, and the car decelerates at $$-3.75\ \mathrm{m/s^2$}$$ after the brakes are applied. What is the total stopping distance from the moment the driver sees the obstacle?

Accepted Answer

$$56.7\ \mathrm{m}$$

Question 9

Which of the following equations is NOT a valid kinematic equation for motion with constant acceleration?

Accepted Answer

$$x = x_0$ + v t + \frac{1}{2} a t^2$

Question 10

A position vs. time graph for a car is a straight line with a positive slope. What does this indicate about the car's motion?

Accepted Answer

The car is moving at a constant positive velocity.

Question 11

A velocity vs. time graph for an object is a horizontal line at $$v = 0. $$What does this indicate about the object's motion?

Accepted Answer

The object is at rest.

Question 12

A car starts from rest and accelerates uniformly at $$2.0\ \mathrm{m/s^2$}$$ for $$5.0\ \mathrm{s}. $$What is its final velocity?

Accepted Answer

$$10.0\ \mathrm{m/s}$$

Question 13

A stone is dropped from a height of $$20.0\ \mathrm{m}. $$How long does it take to reach the ground? (Ignore air resistance.)

Accepted Answer

$$2.02\ \mathrm{s}$$

Question 14

Which of the following best describes the relationship between speed and velocity?

Accepted Answer

Speed is the magnitude of velocity.

Question 15

A truck travels at a constant speed of $$15\ \mathrm{m/s}. At $$the same instant, a car at rest at a traffic light begins to accelerate at $$2.0\ \mathrm{m/s^2$} as $$the light turns green. How far from the light will the car catch up to the truck?

Accepted Answer

$$112.5\ \mathrm{m}$$

Question 16

On a velocity vs. time graph, what does the area under the curve represent?

Accepted Answer

Displacement

Question 17

A cat jumps from a shelf $$1.37\ \mathrm{m}$$ above the ground. What is its speed just before it lands? (Ignore air resistance.)

Accepted Answer

Question 18

If an object’s velocity and acceleration are in opposite directions, what happens to the object’s speed?

Accepted Answer

The object slows down.

Chapter 2: Motion Along a Straight Line – Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard