A boy takes 2 second to reach the maximum speed of 18 km/h from rest. What is the magnitude of his average acceleration ?

Answer

B

Explanation

Initial velocity
u=0
(Since starts from rest)
FiN/Al velocity
v=18km/hr=5sec
(i.e. maximum velocity)
Time inteval
t=2 sec.
`:. Acceleration = a_(av)=((v-u))/2
=5/2= 2.5m/s^2`