- #1
ZxcvbnM2000
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Homework Statement
One snooker ball (initially traveling at 0.6 m s-1) hits another of the same mass (0.4 kg) which was initially at rest. They collide with a coefficient of restitution of 0.9. The balls do not collide head-on, and so they come away at different angles. If the final speed of the incident ball is 0.3 m s-1, what is the final speed of the other (originally stationary) ball?
Homework Equations
conservation of momentum on x,y axis
law of restitution on the line of impact
The Attempt at a Solution
Momentum is conserved on the y-axis ( perpendicular to the line of impact )
so u1cosφ=V1cosθ + V2 1)
Momentum is conserved on the x-axis ( the line of impact )
u1sinφ= V1sinθ 2)
Applying the law of restitution on the line of impact :
e= ( V2-V1cosθ)/(u1cosφ) 3)
So if we re-arrange a bit we get :
0.6cosφ = 0.3cosθ + V2
0.54cosφ = -0.3cosθ + V2
Αnd if we subtract these two we get :
cosφ = 10cosθ 4)
Νow if we plug 4) to 0.6cosφ = 0.3cosθ + V2 we get :
5.7cosθ=V2
But we also know that from 1) & 3) V2 is also equal to = ((e+cosφ)u1)/2 so
i found that cosθ=0.1 and i then i plugged it to 5.7cosθ=V2 and found that V2 is 0.57 m/s .
Is my solution correct ?
Thank you :)