Question 1

A car moves along a straight road and its position is recorded every second. The distance between each recorded position increases with each second. Which of the following best describes the car's motion?

Accepted Answer

The car is speeding up.

Question 2

A ball is thrown straight up into the air. At the very top of its trajectory, what is the direction of its acceleration vector?

Accepted Answer

It points down.

Question 3

Which of the following statements about average velocity is correct?

Accepted Answer

Average velocity is defined as $$\frac{\Delta \vec{r}}{\Delta t}$$, where $$\Delta \vec{r} is $$the displacement vector.

Question 4

A cyclist travels 100 m east in 20 s, then 100 m west in 20 s. What is the cyclist's average velocity for the entire trip?

Accepted Answer

$$0\ \mathrm{m/s}$$

Question 5

A rocket is launched vertically with an acceleration of $$30\ \mathrm{m/s^2$}$$ for $$4\ \mathrm{s}$$ before running out of fuel. Neglecting air resistance, what is the rocket's velocity immediately after the fuel runs out?

Accepted Answer

$$120\ \mathrm{m/s}$$

Question 6

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

Accepted Answer

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

Question 7

A motion diagram shows dots that are equally spaced along a straight line. What does this indicate about the object's motion?

Accepted Answer

The object is moving at constant speed.

Question 8

A student walks 200 m north in 4 minutes, stops for 2 minutes, then walks 100 m south in 2 minutes. What is the student's average speed for the entire trip?

Accepted Answer

$$30\ \mathrm{m/min}$$

Question 9

Which of the following best describes the particle model in physics?

Accepted Answer

It represents an object as a mass concentrated at a single point.

Question 10

A car accelerates from rest up a $$20^\circ$$ hill with a constant acceleration. Which of the following statements is true about the direction of the velocity and acceleration vectors?

Accepted Answer

Both vectors point up the hill.

Question 11

If an object is slowing down while moving to the right, what is the direction of its acceleration vector?

Accepted Answer

To the left

Question 12

Which of the following is the correct formula for the area of a circle?

Accepted Answer

$$A = \pi r^2$

Question 13

A position-versus-time graph for a car shows a straight line with a negative slope. What does this indicate about the car's motion?

Accepted Answer

The car is moving at constant speed to the left.

Question 14

Which of the following is a correct order-of-magnitude estimate for the mass of a human?

Accepted Answer

$$100\ \mathrm{kg}$$

Question 15

A runner travels 400 m in 50 s. What is her average speed in m/s, and what is the correct number of significant figures in the answer?

Accepted Answer

$$8.0\ \mathrm{m/s}$$, 2 significant figures

Question 16

Which of the following is the correct formula for the Pythagorean theorem?

Accepted Answer

$$c^2$$ = $$a^2$$ + $$b^2$$

Question 17

A car moves with a constant velocity of $$20\ \mathrm{m/s}$$ for $$10\ \mathrm{s}. $$What is its displacement?

Accepted Answer

$$200\ \mathrm{m}$$

Question 18

Which of the following is the correct SI prefix for $$10^{-6}$$?

Accepted Answer

micro-

Question 19

A student converts $$1.00$$ mile to kilometers using the conversion factor $$1\ \mathrm{mi} = 1.609\ \mathrm{km}. $$What is the result, and how many significant figures should it have?

Accepted Answer

$$1.61\ \mathrm{km}$$, 3 significant figures

Question 20

Which of the following best describes the direction of the acceleration vector when an object is speeding up in the direction of its velocity?

Accepted Answer

The acceleration vector points in the same direction as the velocity vector.

Chapter 1: Concepts of Motion – Physics Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard