Question

Find the momentum of a body of mass 100g having kinetic energy 500j

Answer 1

100g=0.1kg
K E =1/2mv^2
momentum p=mv
KE=p^2/2m
p^2=2*0.1*500
p=10kg m/s

Answer 2

MOMENTUM IS 100 kg m/s.

Given:

• Mass = 100 g = 0.1 kg
• Kinetic Energy = 500 J

To find:

• Momentum of object?

Calculation:

We know that Kinetic Energy is written as:

$KE = \dfrac{1}{2} \times m \times {v}^{2}$

• Now, we also know that momentum (P) = m × v.

$\implies KE = \dfrac{1}{2} \times \dfrac{{m}^{2} \times {v}^{2} }{m}$

$\implies KE = \dfrac{1}{2} \times \dfrac{{(mv)}^{2} }{m}$

$\implies KE = \dfrac{1}{2} \times \dfrac{{P}^{2} }{m}$

$\implies KE = \dfrac{{P}^{2} }{2m}$

$\implies {P}^{2} = 2m \times KE$

$\implies P= \sqrt{ 2m \times KE }$

$\implies P= \sqrt{ 2 \times 0.1 \times 500 }$

$\implies P= \sqrt{ 100}$

$\implies P=10 \: kg \: m/s$

So, momentum of object is 100 kg m/s