Question

a car travelling at 60 km per hour uniformly retards for 10 seconds and attain a velocity of 45 km per hour find retardation

Answer 1

initial velocity ( u ) = 60 km/hr final velocity ( v ) = 45 km/hr time ( t )= 10 sec     as   a =  {v - u} / t     = (45 - 60)/ 10           = -15/10 so,  retardation ( a ) = - 1.5 m/sec^2  #hope it helps

Answer 2

Hello user

Using the first equation of motion,we have

v=u+at

Here , t is 10 sec = 1/6 hours

So,

45 = 60 + 1/6 × a
a = -15 × 6 = -90 km/hr

So, retardation will be 90 km/hr