Question

a car starts from rest and accelerate uniformly for 20s attain a speed of 25 metre per second it maintains this speed for 30s before decelerating uniformly to rest the total journey is 60s find the total distance traveled and deceleration of the air

Answer 1

distance while accelerating is

d=(v+u)t/2

=25*20/2

=250 m

distance while uniform speed is

d= vt

= 25*30

= 750 m

distance while retardation is

d=(v+u)t/2

= 25*10/2

=125 m

So distance travelled = 1125 m

Retardation = (v-u)/t=25/10=2.5 m/s²

Hope this helps