Question

An airplane takes off 12.5 miles south of a city and flies due north at a constant speed of 170 miles per hour. What is the plane’s position relative to the city after 45 minutes?

A) 115 miles south

B) 115 miles north

C) 140 miles south

D) 140 miles north

Answer 1

Option B

Explanation:

Speed is distance moved per unit tine and is expressed as s=d/t

Making d the subject then

d=st

Where d is distance, s is speed and t is time taken in time.

Conversion

1 hour has 60 minutes hence 45 mins converted to hours will be 45/60=0.75

Substituting 0.75 hours for t and 170 mph for s then

d=0.75*170=127.5 miles due North

However, tge plane had initially moved 12.5 miles hence the relative distance due North will be 127.5-12.5=115 miles due North