A walker completes a  $2.4 \mathrm{~km}$ route in 30 minutes. What is the walker's average speed in  $\mathrm{km} / \mathrm{h}$ for this distance?

A car starts from rest, accelerates uniformly for 5 seconds, travels at constant velocity for 5 seconds, and finally decelerates uniformly for 5 seconds. Sketch graphs of velocity versus time and acceleration versus time for this situation.

A car accelerates uniformly for 5 seconds, then travels at constant velocity for 5 seconds before decelerating uniformly for 5 seconds. Create velocity versus time and acceleration versus time graphs for this situation.

A graph of x versus

$$t^4$$

, with x on the vertical axis and

$$t^4$$

on the horizontal axis, is linear. Its s lope is 25

$$m/s^4$$

and its vertical axis intercept is 3 m. Write an equation for x as a function of t.

A traveler covers a distance of 460 miles in a time of 8 hours. What is the average speed for this trip?A traveler covers a distance of 460 miles in a time of 8 hours. What is the average speed for this trip?

A car moves along a straight section of road so that its velocity varies with time as shown in the graph. a. Does the car ever go backward? Explain.

Does a car's speedometer show instantaneous speed, average speed, or velocity? Explain.

When stopped by police, a driver claims she was doing 80 mph. Is that an unequivocal statement? Would this be interpreted differently in the UK than in the US? Explain.

A car travelling at a constant speed rounds a highway curve. Is the car's acceleration equal to zero in this situation? Explain.

A car accelerates for 5 seconds at a constant rate of $4.0 \mathrm{~m} / \mathrm{s}^2$ after starting from rest. a. Determine the car's velocity at each of the following mathrm values:  $1 \mathrm{~s}, 2 \mathrm{~s}, 3 \mathrm{~s}, 4 \mathrm{~s}$, and $5 \mathrm{~s}$, and plot these values versus time. b. Calculate the car's distance for these similar times and plot the values of the distance against time.

How long would it take a world-class sprinter to complete a distance of 100 metres if he started at his highest pace of  $9 \mathrm{~m} / \mathrm{s}$ and maintained it throughout?

Two cars, one twice the size of the other, are travelling at different speeds at the same time. Is it possible to say which of these two cars has the greater acceleration at this point in time based on this information? Explain.

A car driver applies the brakes, causing the vehicle's velocity to decrease. Does the car accelerate during this process, according to the definition of acceleration provided in this chapter? Explain.

Over the course of two seconds, a runner who began at a constant speed of $-1.6 \mathrm{~m} / \mathrm{s}^2$  slows down from an initial velocity of  $4.0 \mathrm{~m} / \mathrm{s}$ a .What was her speed at the end of this period? b. How far does she travel throughout this procedure?