Q: Which formula correctly expresses acceleration?

$$a = \frac{\text{Change in velocity}}{\text{Change in time}}$$

Q: A river flows east at $$20 \ \mathrm{km/h}$$ and you swim west at $$5 \ \mathrm{km/h}$$ relative to the water. What is your velocity relative to the ground?

$$15 \ \mathrm{km/h}$$ \ \text{east}

Q: A ball is thrown straight up with an initial velocity of $$30 \ \mathrm{m/s}. $$What is its velocity after $$2$$ seconds? (Assume $$g = 10 \ \mathrm{m/s^2$}$$ downward)

$$10 \ \mathrm{m/s}$$ \ \text{upward}

Question 1

A car travels 120 km in 2 hours. What is its average speed?

Accepted Answer

$$60 \ \mathrm{km/h}$$

Question 2

Which of the following best describes instantaneous speed?

Accepted Answer

The speed at any particular moment in time

Question 3

A runner completes a 400 m lap in 50 seconds. What is her average speed?

Accepted Answer

$$8 \ \mathrm{m/s}$$

Question 4

Which statement about velocity is correct?

Accepted Answer

Velocity is speed with direction

Question 5

A car moves east at $$20 \ \mathrm{m/s}$$ for 10 seconds, then west at $$10 \ \mathrm{m/s}$$ for 10 seconds. What is the car's average velocity over the 20 seconds?

Accepted Answer

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

Question 6

Which of the following scenarios describes constant velocity?

Accepted Answer

A car moving in a straight line at constant speed

Question 7

What is the acceleration of an object in free fall near Earth's surface?

Accepted Answer

$$a = 9.8 \ \mathrm{m/s^2$}$$

Question 8

A motorcycle accelerates from $$5 \ \mathrm{m/s} to$$ $$25 \ \mathrm{m/s} in$$ $$4$$ seconds. What is its acceleration?

Accepted Answer

$$5 \ \mathrm{m/s^2$}$$

Question 9

Which formula correctly expresses acceleration?

Accepted Answer

$$a = \frac{	ext{Change in velocity}}{	ext{Change in time}}$$

Question 10

A ball is dropped from rest. What is its velocity after $$2$$ seconds? (Assume $$g = 10 \ \mathrm{m/s^2$})$$

Accepted Answer

$$20 \ \mathrm{m/s}$$

Question 11

A ball is dropped from rest. What is the distance it falls after $$3$$ seconds? (Assume $$g = 10 \ \mathrm{m/s^2$})$$

Accepted Answer

$$45 \ \mathrm{m}$$

Question 12

A river flows east at $$20 \ \mathrm{km/h}$$ and you swim west at $$5 \ \mathrm{km/h}$$ relative to the water. What is your velocity relative to the ground?

Accepted Answer

$$15 \ \mathrm{km/h}$$ \ 	ext{east}

Question 13

An airplane flying at $$150 \ \mathrm{km/h} is $$caught in a $$100 \ \mathrm{km/h}$$ crosswind. What is the resultant velocity?

Accepted Answer

$$250 \ \mathrm{km/h}$$

Question 14

Which of the following is NOT a way to change the velocity of an object?

Accepted Answer

Keeping both speed and direction constant

Question 15

A car travels 100 km north, then 100 km south in 4 hours. What is its average velocity?

Accepted Answer

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

Question 16

If a car moves at a constant speed but changes direction, what can be said about its velocity?

Accepted Answer

Velocity is changing

Question 17

A ball is thrown straight up with an initial velocity of $$30 \ \mathrm{m/s}. $$What is its velocity after $$2$$ seconds? (Assume $$g = 10 \ \mathrm{m/s^2$}$$ downward)

Accepted Answer

$$10 \ \mathrm{m/s}$$ \ 	ext{upward}

Question 18

Which of the following is true about free fall?

Accepted Answer

The acceleration is constant and equal to $$g$$

Ch.03 – Linear Motion: Study Notes

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드