Q: A car travels 120 km east in 2 hours, then 150 km north in 3 hours. What is the magnitude of the car's net displacement from its starting point?

$$\sqrt{(120^2$ + 150^2$)} = 192\ \text{km}$$

Q: A runner jogs 400 m east, then 300 m north. What is the direction of the runner's net displacement from the starting point?

$$\theta = \tan$$^{-1}$$\left(\frac{300}{400}\right) = 37$$^{\circ}$$ north of east

Q: If a cyclist moves from $$x_i = 3\ \text{mi}$$ east of a water tower to $$x_f = -2\ \text{mi}$$ west of the tower in 0.5 hours, what is her displacement?

$$\Delta x = x_f - x_i = -2 - 3 = -5\ \text{mi}$$

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

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

Q: A car moves at a constant velocity of $$20\ \text{m/s}$$ for $$15\ \text{s}. $$What is the total displacement?

$$d = v t = 20 \times 15 = 300\ \text{m}$$

Q: Convert $$6,370,000$$ meters to scientific notation.

$$6.37 \times 10^6$\ \text{m}$$

Question 1

A car travels 120 km east in 2 hours, then 150 km north in 3 hours. What is the magnitude of the car's net displacement from its starting point?

Accepted Answer

$$\sqrt{(120^2$ + 150^2$)} = 192\ 	ext{km}$$

Question 2

Which of the following statements best describes the difference between speed and velocity?

Accepted Answer

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

Question 3

A runner jogs 400 m east, then 300 m north. What is the direction of the runner's net displacement from the starting point?

Accepted Answer

$$	heta = 	an$$^{-1}$$\left(\frac{300}{400}ight) = 37$$^{\circ}$$ north of east

Question 4

If a cyclist moves from $$x_i = 3\ 	ext{mi}$$ east of a water tower to $$x_f = -2\ 	ext{mi}$$ west of the tower in 0.5 hours, what is her displacement?

Accepted Answer

$$\Delta x = x_f - x_i = -2 - 3 = -5\ 	ext{mi}$$

Question 5

A ball is thrown at a $$60^{\circ}$$ angle above the horizontal. Which of the following best describes the velocity vectors during its flight?

Accepted Answer

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

Question 6

Which of the following is a vector quantity?

Accepted Answer

Displacement

Question 7

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

Accepted Answer

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

Question 8

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

Accepted Answer

Kilogram (kg)

Question 9

A car moves at a constant velocity of $$20\ 	ext{m/s}$$ for $$15\ 	ext{s}. $$What is the total displacement?

Accepted Answer

$$d = v t = 20 	imes 15 = 300\ 	ext{m}$$

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 measurement is recorded as $$0.0520. $$How many significant figures does this value have?

Accepted Answer

3

Question 12

A student walks 100 m east, then 200 m west. What is the net displacement vector?

Accepted Answer

100 m east + 200 m west = 100 m west

Question 13

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

Accepted Answer

Temperature

Question 14

A runner completes one lap around a 400 m track in 100 s. What is the average velocity?

Accepted Answer

0 m/s

Question 15

Convert $$6,370,000$$ meters to scientific notation.

Accepted Answer

$$6.37 	imes 10^6$\ 	ext{m}$$

Question 16

A person walks 1 mile in 30 minutes. Estimate their speed in meters per second. (1 mile $$\approx 1600 m)$$

Accepted Answer

$$\frac{1600}{1800} \approx 0.89\ 	ext{m/s}$$

Question 17

Which of the following is true about time intervals in physics?

Accepted Answer

A time interval is always positive.

Question 18

If a vector has components $$3$$ units east and $$4$$ units north, what is its magnitude?

Accepted Answer

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

Question 19

Which of the following best describes the process of adding two vectors graphically?

Accepted Answer

Place the tail of the second vector at the tip of the first, then draw the resultant from the tail of the first to the tip of the second.

Chapter 1: Representing Motion – Physics with Calculus Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard