Question

A constant retardation of 2.5 m/s^2 is applied to a body of mass 20kg moving initially with a speed of 15m/s how long does the body take to stop

Answer 1

Answer:

19 second s body will take

Answer 2

Answer:  The time required to stop the body in the given conditions is 6 seconds.

Explanation:

Acceleration acting on the body = - 2.5 m/s².

Note the negative sign is because the acceleration is acting opposite to the motion of the body

Mass of the body = 20 kg.

Initial speed of the body = 15m/s.

Now, using the equations of motion we can write:

v = u + at --------------------------(1)

Where,

v = final velocity equal to zero as the particles come to rest ultimately.

u = initial velocity of the body.

a = acceleration of the body.

t = time taken to reach from initial to the final velocity of the body.

So, from equation (1) we get

   0 = 15 + (-2.5)t

=> t = $\frac{15}{2.5}$ = 6 seconds.

Therefore, the time required to stop the body in the given conditions is 6 seconds.