Question

The ships were 400miles apart at midnight and were headed directly toward each other. if they collided at 8 am, find the speed of both ships if one was 20 miles per hour faster.

Answer 1

v1=15mph, v2=35mph

Explanation:

We have the values:

s=400mi (distance travelled)

t=8h (time)

v1=x, v2=x+20 (first and second speed)

We need to work out v1 and v2.

The formula for time is equal to distance over speed. t=s/v

Because the two ships are colliding, the formula will be t=s/v1+v2

Plug in given values:

8h=400mi/x+x+20

8h=400mi/2x+20

Cross multiply:

400=8(2x+20)

400=16x+160

-16x=-240 (Divide by -16)

x=15, which means that v1=15mph

To work out v2, all we must do is add 20 to 15mph and we get v2=35mph.

Hope this helps!