If the brakes are applied and the speed of the car is reduced to 12 m/s in 15 s , determine the constant deceleration of the car.

Given:

= 12 m/s

Time = 15 s

To find:

Deceleration = ?

Formula used:

Deceleration is given by,

a =

Solution:

Acceleration of the body is rate of increase of velocity. Deceleration of the body is negative acceleration i. e rate of decrease of velocity.

Thus, deceleration of the body is given by,

a =

where a is the deceleration of the body

v is the velocity

is rate of change of velocity

t is the time

a =

a = 0.8 m/

Thus, deceleration is 0.8 m/ .

at positions a, g kinetic energy is maximum.

at position d, potential energy is maximum.