Question

A car is travelling with a speed of 36 km/h. The driver applied the brakes and retards the car uniformly. The car is stopped in 5 sec. Find (i) The acceleration of car and (ii) Distance before it stops after Appling breaks?

Answer 1

v=u+at

v=0

u=36km/hr=10m/s

0= 10+5a

a=-2m/s^2

S=ut+1/2at^2

=50-25

S=25m

Answer 2

u=36km/h=10m/s

t=5s

v=0m/s

1). a=(v-u)/t

a=(0-10)/5

a=-10/5=-2m/s²

so,retardation is 2m/s².

2). v²=u²+2aS

0²=10²+2*(-2)*S

0=100-4*S

S=-100/-4=25m