Q: A car travels 60 km in 0.75 hours. What is its average speed in m/s?

$$\frac{60\,\text{km}}{0.75\,\text{h}} = 80\,\text{km/h} = 22.2\,\text{m/s}$$

Q: A student walks 3 m east, then 4 m north. What is her net displacement from the starting point?

$$\sqrt{3^2$ + 4^2$} = 5\,\text{m}$$

Q: A goose flies 21 mi east, then 28 mi north. What is the straight-line distance from its starting point to the lake?

$$\sqrt{21^2$ + 28^2$} = 35\,\text{mi}$$

Q: A runner jogs along a track. At $$t=0 s$$, she is at $$x=0 m. At$$ $$t=10 s$$, she is at $$x=50 m. $$What is her average velocity?

$$\frac{50\,\text{m}}{10\,\text{s}} = 5\,\text{m/s}$$

Q: A student walks 90 m east and then 50 m north. What is the angle of her net displacement north of east?

$$\theta = \tan$$^{-1}$$\left(\frac{50}{90}\right) = 29^\circ$$

Question 1

A runner jogs 100 m east, then 200 m west. What is the magnitude and direction of her displacement?

Accepted Answer

100 m, west

Question 2

Which of the following statements correctly distinguishes between speed and velocity?

Accepted Answer

Velocity contains information about the direction of motion while speed does not.

Question 3

A car travels 60 km in 0.75 hours. What is its average speed in m/s?

Accepted Answer

$$\frac{60\,	ext{km}}{0.75\,	ext{h}} = 80\,	ext{km/h} = 22.2\,	ext{m/s}$$

Question 4

Which of the following is a vector quantity?

Accepted Answer

Displacement

Question 5

A student walks 3 m east, then 4 m north. What is her net displacement from the starting point?

Accepted Answer

$$\sqrt{3^2$ + 4^2$} = 5\,	ext{m}$$

Question 6

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

Accepted Answer

Kilogram (kg)

Question 7

A ball is thrown at a $$60^\circ$$ angle from the horizontal and caught at the same height. Which statement best describes the velocity vectors during its flight?

Accepted Answer

The velocity vectors change in both magnitude and direction throughout the flight.

Question 8

A quantity $$2.67 	imes 10^5$ has how many significant figures?

Accepted Answer

3

Question 9

A goose flies 21 mi east, then 28 mi north. What is the straight-line distance from its starting point to the lake?

Accepted Answer

$$\sqrt{21^2$ + 28^2$} = 35\,	ext{mi}$$

Question 10

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

Accepted Answer

It treats a moving object as if all its mass were concentrated at a single point.

Question 11

A runner jogs along a track. At $$t=0 s$$, she is at $$x=0 m. At$$ $$t=10 s$$, she is at $$x=50 m. $$What is her average velocity?

Accepted Answer

$$\frac{50\,	ext{m}}{10\,	ext{s}} = 5\,	ext{m/s}$$

Question 12

Which of the following is an example of a scalar quantity?

Accepted Answer

Temperature

Question 13

A student walks from $$x=23 m $$and undergoes a displacement $$\Delta x = -50 m. $$What is her final position?

Accepted Answer

$$-27 m$$

Question 14

Which of the following is the correct way to add two displacement vectors $$\vec{A}$$ and $$\vec{B}$$?

Accepted Answer

Place the tail of $$\vec{B} at $$the tip of $$\vec{A}$$ and draw the resultant from the tail of $$\vec{A} to $$the tip of $$\vec{B}.$$

Question 15

A person walks 1 mile northeast, then 1 mile south. What is the magnitude of her net displacement?

Accepted Answer

$$\sqrt{(1)^2$ + (1)^2$ - 2 \cdot 1 \cdot 1 \cdot \cos(45^\circ)} \approx 1.62$$ miles

Question 16

Which of the following is the correct scientific notation for the number 0.0000075?

Accepted Answer

$$7.5 	imes 10$$^{-6}$$

Question 17

A student walks 90 m east and then 50 m north. What is the angle of her net displacement north of east?

Accepted Answer

$$	heta = 	an$$^{-1}$$\left(\frac{50}{90}ight) = 29^\circ$$

Question 18

Which of the following best describes the process for determining the number of significant figures in a multiplication?

Accepted Answer

The answer should have the same number of significant figures as the value with the fewest significant figures.

Chapter 1: Representing Motion – College Physics Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard