Question

An aeroplane is 528 ft directly above an automobile and starts east at the rate of 20 miles an hour at the same instant the automobile starts east at the rate of 40 miles an hour. How fast are they separating

Answer 1

Answer: 20 mph

Explanation:

Given

The airplane is at a height of 528 ft with a rate of 20 mph

The automobile is also directing east at the rate of 40 mph

at this instant, they are separating by the relative velocity between them

`\Rightarrow v_(rel)=40-20=20\ mph`