Question

A car drives east along a road at a constant speed of 46 miles per hour. At 4:00 P.M., a truck is 264 miles away, driving west along the same road at a constant speed. The vehicles pass each other at 7:00 P.M. What is the speed of the truck

Answer 1

The speed of the truck is 42 mph

Explanation:

we know that

The speed is equal to divide the distance by the time

Let

s -----> the speed in miles per hour

d ----> the distance in miles

t ----> the time in hours

`s=(d)/(t)`

`d=s(t)`

step 1

Find out the distance traveled by the car at 7:00 P.M

we have

`s=46\ (mi)/(h)`

`t=7:00 P.M-4:00 P.M=3\ h`

`d=s(t)`

substitute the values

`d=46(3)=138\ mi`

step 2

Find out the speed of the truck

we know that

At 7:00 P.M the distance is equal to

`d=264-138=126\ mi`

`t=7:00 P.M-4:00 P.M=3\ h`

substitute

`s=(126)/(3)`

`s=42\ (mi)/(h)`