A ball of mass 
moving with velocity 
makes an oblique elastic collision with a stationary ball of mass 2
The angle of divergence between the balls after collision in ground frame, if the ball of mass 
turns by an angle of 
in centre of mass frame is
a)
b)
c)
d)
A ball of mass moving with velocity makes an oblique elastic collision with a stationary ball of mass 2 The angle of divergence between the balls after collision in ground frame, if the ball of mass turns by an angle of in centre of mass frame is
a)
b)
c)
d)
Question ID - 100211 | SaraNextGen Answer
A ball of mass moving with velocity makes an oblique elastic collision with a stationary ball of mass 2 The angle of divergence between the balls after collision in ground frame, if the ball of mass turns by an angle of in centre of mass frame is
a)
b)
c)
d)
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A ball of mass |
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a) |
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b) |
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c) |
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d) |
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(d)
Let us solve this question in 
frame. As the collision is elastic, the magnitude of momenta of all balls remains same after collision in this frame
Velocity of 
frame w.r.t. ground frame is
The momentum diagram in 
frame is drawn as shown in fig.
.png)
Now, velocity of 
after colision in 
frame is 
while that of 
is 
along 
and 
, respectively. Let 
and 
be the velocities of 
and 
, respectively after collision in ground frame, then velocity vector diagrams can be drawn as shown
.png)
Using trigonometry, from upper triangle
From lower triangle:
So, angle of divergence is 
Alternative method Write down conservation of momentum equations, coefficient of restitution equation, energy conservation and use the given conditions
