$$\frac{-20}{80} = -0.25\ \mathrm{ms}^{-1}$$\ \text{(southward)}$

Question 1

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

Accepted Answer

Average speed is the total distance traveled divided by time, while average velocity is the total displacement divided by time.

Question 2

A car travels 100 m east, then 100 m west in 50 seconds. What is the car's average velocity?

Accepted Answer

$$\frac{0}{50} = 0\ \mathrm{ms}^{-1}$$

Question 3

If a runner completes a 400 m lap in 80 seconds, what is their average speed?

Accepted Answer

$$\frac{400}{80} = 5\ \mathrm{ms}^{-1}$$

Question 4

A person walks 60 m north in 30 seconds, then 80 m south in 50 seconds. What is their average velocity for the entire trip?

Accepted Answer

$$\frac{-20}{80} = -0.25\ \mathrm{ms}^{-1}$$\ 	ext{(southward)}$

Question 5

Which of the following is the correct SI unit for average velocity?

Accepted Answer

$$\mathrm{ms}^{-1}$$

Question 6

A cyclist travels 120 m in 40 seconds. What is their average speed?

Accepted Answer

$$\frac{120}{40} = 3\ \mathrm{ms}^{-1}$$

Question 7

If an object moves in a straight line and returns to its starting point after 10 seconds, which of the following is true?

Accepted Answer

Its average velocity is zero.

Question 8

A car moves from $$x_0 = 5$$\ \mathrm{m}$$ to x = 25$$\ \mathrm{m}$$ in 4 seconds. What is its average velocity?

Accepted Answer

$$\frac{25-5}{4} = 5\ \mathrm{ms}^{-1}$$

Question 9

Which scenario would result in a negative average velocity?

Accepted Answer

An object moves in the negative direction without changing direction.

Question 10

A runner completes a 100 m dash in 10 seconds. What is their average velocity if they run straight from start to finish?

Accepted Answer

$$\frac{100}{10} = 10\ \mathrm{ms}^{-1}$$

Fundamentals of Mechanics: Motion, Force, Energy, and Materials

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