Question

starting from rest rohan pressed the accelerator of his car to attain a velocity of 12ms^-1in 30s. then he applies brakes such that the velocity of the car comes down to 8ms^-1 the next 5 s. calculate the acceleration of the car in both the cases

Answer 1

Initial velocity= 12 m/s
final velocity=8 m/s
initial time= 30 s
final time= 5 s

A=fv-iv/ft-it
A= 8-12/5-20 
A=-4/-15
A= 0.16