Question

Find the time taken by the body to move through a distance of 12m
16 A force of 4 acts on a body of mass 2 kg for 4 s. Assuming that the body to be
initially at rest, find its velocity when the force stops acting (ii) the distance
covered in 10 safter the force starts acting​

Answer 1

CORRECT QUESTION.

A force of 4 N acts on a body of mass 2 kg

for 4 seconds.assume that the body is to be

initially at rest.

1) = Find it's Velocity when the force stops acting.

2) = The distance covered in 10 seconds after

the force starts acting.

EXPLANATION.

Let,

Force = 4 N

mass = 2 kg

by using the formula,

F = MA

4 = 2a

a = 2 m/s^2

initial velocity = u = 0

Time = 4 seconds

From Newton first equation of

kinematics.

V = u + at

=> V = 0 + 2 X 4

=> V = 8 m/s

Now,

From Newton third equation of

kinematics.

v^2 = u^2 + 2as

=> ( 8) ^2 = 0 + 2 X 2 X s

=> 64 = 4s

=> s = 16 m

It is the distance which covered in 4 seconds

Now, distance covered in 6 seconds

v = u = 8 m/s,

t = 10 - 4 = 6 seconds

a = 0

From Newton second equation of

kinematics.

S = Ut + 1/2 at^2

=> S = 8 X 6 + 0

=> s = 48 m

Therefore,

Total distance covered in 10 second

= 48 + 16 = 64 m

Velocity when force stops acting = 8 m/s