2 rockets fly from 2 places, 1317 miles apart. 1 flies at a speed of 9000 mph, the other at 21000. What is the distance between them 1 minute before collision?

Question

This is a question from my homework but I am not sure how to do it. Please help.

Answer 1

distance=rate*time

1317=9000t+21,000t

1317=30,000t

t=1317/30,000

t=0.0439 hours

the rockets are flying for 0.0439 hours or 0.0439*60=2.634 minutes

t=2.634 minutes

1 minute before collision means that they are flying for only 2.634-1=1.634 minutes

1.634 minutes is 1.634/60=0.0272333... hours

d=r*t

d=9000*0.0272333=245.1 miles

d=21,000*0.0272333=571.9 miles

245.1+571.9=817 miles flown towards each other

they are 1317 miles apart

1317-817=500 miles

they are 500 miles apart 1 minute before collision

check:1 minute is 1/60 of an hour

In 1 minute can the rockets fly a total of 500 miles and collide ?

d=r*t

d=9000*(1/60)=150 miles

d=21,000*(1/60)=350 miles

150+350=500 miles