A cyclist is moving along a  circular  path  of radius 25 m with a constant velocity of 60 m /s. He suddenly applies breaks, till he stops. The breaks provide a tangential deceleration of 5 m /s2 . Find his acceleration after 2 seconds.

a) 12.00 m /s2 .
b) 11.18 m /s2.
c) 100.12 m /s2
d) 101.20 m /s2.

 

The tangential deceleration of the cyclist when he
applies breaks is 5 m / s2 . His velocity at t = 2 s, v2
can be obtained from,

   v f = v 0 + a t
hence,
   v 2 = 60 + ( - 5 ) 2 = 50 m / s.

The acceleration at t = 2 s consists of the tangential
acceleration, a t , and the normal acceleration, a n .


The magnitude of the acceleration experienced by the cyclist is 100.12 m /s2 , at the instant t = 2 s .