Question

A mass o 3 grams is moving with a constant velocity of 4m/sec.its kinetic energy is

Answer 1

Heya!

mass=3 gm= 0.003 kg

v= 4m/s

Then,

K.E. =1/2 * m * v^2

=1/2 * 0.003 * 4^2

=1/2 * 0.003 * 16

=0.003 * 8

=0.024 J

Hope it helps u.

Answer 2

Given,

Mass of a body = 3 g,

It is moving with velocity = 4 m/s.

To find,

Its kinetic energy.

Solution,

Kinetic energy is defined as the energy of a body because of the motion of the body.

Kinetic energy (KE) of a body (in joules), is given by the relation,

$KE=\frac{1}{2} mv^2$     ...(1)

Where,

m = mass of the body (kg),

v = velocity with which it is moving (m/s).

Here, we first need to convert the mass into SI units so as to get KE in joules.

Since 1 kg = 1000 g,

⇒ 1 g = 0.001 kg

The given mass is 3 g.

⇒ 3 g = 0.003 kg.

Now, substituting the given values,

m = 0.003 kg

v = 4 m/s, in the equation (1), we get,

$KE=\frac{1}{2} (0.003)\cdot (4^2)$

⇒ $KE=\frac{1}{2} (0.003)\cdot (16)$

⇒ $KE=\frac{1}{2} (0.048)$

⇒ KE = 0.024 J.

Therefore, the kinetic energy of the given body is 0.024 J.