Question

particle of mass 0.2 kg is moving with velocity 4 m/s towards east and another particle of mass 0.1 kg is moving west on the same straight line with velocity 5 m/s.What is the velocity of centre of mass before collision :​

Answer 1

Explanation:

we are solving this question from 'equation of conservation of momentum'

m1=0.2, v1=4, m2=0.1, v2=5

putting value in equation...

Answer 2

Given :

Initial velocity of particle of mass 0.2kg = 4m/s

Initial velocity of particle of mass 0.1kg = -5m/s

[Here negative sign indicates opposite direction]

To Find :

Velocity of centre of mass before collision.

Solution :

❖ Centre of mass is an imaginary point where the whole mass of system can be assumed to be concentrated.

Velocity of COM of the two particle system is given by

$\dag\:\underline{\boxed{\bf{\purple{v_{COM}=\dfrac{m_1v_1+m_2v_2}{m_1+m_2}}}}}$

By substituting the given values;

$\sf:\implies\:v_{COM}=\dfrac{(0.2)(4)+(0.1)(-5)}{0.2+0.1}$

$\sf:\implies\:v_{COM}=\dfrac{0.8-0.5}{0.3}$

$\sf:\implies\:v_{COM}=\dfrac{0.3}{0.3}$

$:\implies\:\underline{\boxed{\bf{\orange{v_{COM}=1\:ms^{-1}}}}}$