Question

A parachutist's rate during a free fall reaches 126 miles per hour. What is the rate in ft per sec? At this rate, how many ft will the parachutist fall during 2 secs of free fall?

a) 184.8 ft/s, 369.6 ft
b) 183.6 ft/s, 367.2 ft
c) 125.0 ft/s, 250.0 ft
d) 127.4 ft/s, 254.8 ft

Answer 1

To convert 126 mph to ft/s, multiply by the conversion factors to get 184.8 ft/s. Multiplying this rate by 2 seconds results in a fall of 369.6 feet, thus the correct answer is (a) 184.8 ft/s, 369.6 ft.

Step-by-step explanation:

The question involves converting a velocity from miles per hour to feet per second and then calculating the distance fallen in a given time using the rate.

To convert 126 miles per hour to feet per second, use the following relationships:
1 mile = 5280 feet,
1 hour = 3600 seconds.

126 miles/hour × 5280 feet/mile × 1 hour/3600 seconds = 184.8 feet per second (ft/s).

Then, to find out how far the parachutist falls in 2 seconds:

184.8 ft/s × 2 s = 369.6 feet.

Therefore, the correct answer is (a) 184.8 ft/s, 369.6 ft.