Question

A parachutist's rate during a free fall reaches 90 miles per hour. What is this rate in feet per second? At this rate, how many feet will the parachutist fall during 2seconds of free fall? In your computations, use the fact that I mile is equal to 5280 feet. Do not round your answers.

Answer 1

Rate in feet per second: 132 ft/sec

Distance (in feet) fall in first two seconds: 264 ft

Explanation:

Answer 2

The rate at which parachutist fall is 90 miles per hour.

Determine the rate of fall in miles per seconds.

`90\text{ mi/hr}*\frac{1\text{ mi/sec}}{3600\text{ mi/hr}}=(1)/(40)\text{ mi/sec}`

Determine the miles fall in 2 seconds.

`(1)/(40)\text{ mi/sec}*2\text{ sec=}(1)/(20)\text{ miles}`

Convert 1/20 miles into feet.

`(1)/(20)\text{ miles}*\frac{5280\text{ feet}}{1\text{ mile}}=264\text{ feet}`

So parachutist fall 264 feet during 2 seconds of free fall.

Determine the rate of fall in feet per second.

`\begin{gathered} \text{90 miles/hour}=90\text{ miles/hr}*\frac{(5280)/(3600)\text{ ft/sec}}{1\text{ miles /hr}} \\ =132\text{ ft/sec} \end{gathered}`

Answer:

Rate in feet per second: 132 ft/sec

Distance (in feet) fall in first two seconds: 264 ft