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

Answer:

87.5mph

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  = $\frac{Final speed - Starting speed }{time }$

Insert the parameters and solve;

 7.5  = $\frac{Final speed - 50 }{5 }$

  Final speed - 50  = 7.5 x 5

  Final speed  = 7.5 x 5 + 50  = 87.5mph