Question

A rocket car accelerates 4.5 m/s squared over 6.00 s to reach the freeway speed at the end of an entrance ramp. if the cars final speed is 75 m/s, what was its initial speed on it begin accelerating?

Answer 1

Use the definition of average acceleration:

`a_(\rm ave)=(\Delta v)/(\Delta t)`

Then

`4.5(\rm m)/(\mathrm s^2)=(75(\rm m)/(\rm s)-v_i)/(6.00\,\mathrm s)`

`\implies v_i=48(\rm m)/(\rm s)`