Editor Staff asked 1 year ago
Two bodies of masses 5 kg and 3 kg are moving towards each other at velocities of 3 m/s and 5 m/s, respectively. What is the velocity of their centre of mass?
(a) 0.25 m/s towards 3 kg
(b) Upredictable
(c) The centre of mass is stationary
(d) 0.5 m/s towards 5 kg
The question was asked in an interview for job.
I would like to ask this question from System of Particles topic in chapter System of Particles and Rotational Motion of Physics – Class 11
Select the correct answer from above options
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Editor Staff answered 1 year ago
The correct option is (c) The centre of mass is stationary
To explain I would say: The velocity of the centre of mass = (m1*v1 + m2*v2)/(m1 + m2)
m1 = 5kg
m2 =3 kg
v1 = 3 m/s
v2 = -5 m/s [opposite direction)
Velocity of centre of mass = (5*3 – 3*5)/(5+3)
= 0.
