Question

A uniform force of 4 newton acts on a body of mass 40 kg and distance 2m the ke aquried is

Answer 1

The kinetic energy of the body is 2880 J.

Explanation:

Given that,

Force, F = 4 N

Mass of the body, m = 40 kg

Time, t = 2 min = 120 s

To find,

Kinetic energy of the body.

Solution,

Force acting on a body is given by :

F = ma

a=\dfrac{F}{m}a=

M

F

a=\dfrac{4}{40}a=

40

4

a=0.1\ m/s^2a=0.1 m/s

2

Initially, the body was at rest, u = 0

Let v is the final velocity of the body. It can be given by :

v=u+atv=u+at

v=0.1\times 120v=0.1×120

v = 12 m/s

Kinetic energy of a body is given by :

K=\dfrac{1}{2}mv^2K=

2

1

mv

2

K=\dfrac{1}{2}\times 40\times (12)^2K=

2

1

×40×(12)

2

K = 2880 J

So, the kinetic energy of the body is 2880 J.