Question

Find the velocity of a body of mass
100 g having kinetic energy 20 J.
Solution :​

Answer 1

Answer:

20 m/s

Explanation:

GIVEN

MASS (m) = 100 g

(1000g= 1 kg => 100g = 100/1000 = 1/10kg)

KINETIC ENERGY (K.E) = 20 J

SOLUTION

we know that,

KINETIC ENERGY = 1/2 m v²

substituting values we get :

20 J = 1/2 1/10 v²

=> 20 = 1/20 V²

=> 20 ÷ 1/20 = v²

=> 20 × 20 = v²

=> 400= v²

=> √400 = v

=> 20 = v

hence,

v = 20 m/s

Answer 2

$\mathtt{ \huge{\fbox{SOLUTION :}}}$

Given ,

Mass of the body = 100 g = 0.1 kg

Kinetic energy of the body = 20 j

We know that , kinetic energy of a body is given by

$\sf \large \fbox{Kinetic \: energy = \frac{1}{2} m {(v)}^{2} }$

Substitute the known values , we obtain

$\sf \hookrightarrow 20 = \frac{1}{2} \times 0.1 \times {(v)}^{2} \\ \\\sf \hookrightarrow 20 = \frac{1}{20} \times {(v)}^{2} \\ \\\sf \hookrightarrow {(v)}^{2} = 400 \\ \\\sf \hookrightarrow v = 20 \: \: m/s$

Hence , the velocity of the body is 20 m/s