Question

If a car accelerates at 7.5 mph/s, what would be its final speed after 5.0 seconds if its

starting speed were 50mph?

Answer 1

87.5mph

Step-by-step explanation:

Given parameters:

Acceleration = 7.5mph/s

Starting speed = 50mph

Time = 5s

Unknown:

Final speed = ?

Solution:

Acceleration is defined as the rate of change of velocity with time:

Acceleration =
`(Final speed - Starting speed )/(time )`

Insert the parameters and solve;

7.5 =
`(Final speed - 50 )/(5 )`

Final speed - 50 = 7.5 x 5

Final speed = 7.5 x 5 + 50 = 87.5mph