MHB Friction: Snooker Ball Mass & Speed Calculation

AI Thread Summary
A snooker ball with a mass of 0.4 kg is struck towards a cushion at a speed of 3 m/s from 0.8 m away, with a coefficient of friction of 0.3. The ball's speed decreases by 20% upon bouncing off the cushion, resulting in a new speed of 1.64 m/s. Calculations show that the ball travels approximately 0.448 m before coming to a stop. The discussion highlights the complexity of determining the effects of rolling versus sliding friction on the ball's motion. Understanding the dynamics of rolling and sliding is essential for accurate calculations in this scenario.
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A snooker ball of mass 0.4kg is struck towards a cushion from 0.8m away with speed 3m/s. The surface of the snooker table has a coefficient of friction of 0.3. When the ball bounces from the cushion its speed is reduced by 20%. Find how far from the cushion it stops.
 
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show your work on this problem, please
 
I have a basic problem with this. A snooker ball primarily rolls with only a slight amount of sliding. The coefficient of friction only applies to the sliding. To answer this you would have to know what part of the motion was sliding and I see no way to determine that.
 
skeeter said:
show your work on this problem, please
m=0.4kg, u=3m/s, coefficient of friction =0.3
By using Newtons law
F=m×a
-0.3×4=0.4a
a=-3m/s^2,
By using v^2=u^2+2as, v=2.05m/s when the ball hits the cushion
The speed decreases by 20%, so 2.05×0.8=1.64m/s. Again using v^2=u^2+2as, I get s=0.25m
 
skeeter said:
show your work on this problem, please
Oh sorry I had done a silly mistake. So initial velocity is 3 and when it hits the cushion, the final velocity is 2.05 m/s , this is reduced by 20% so now u= 1.64 m/s and v=0 ( as the ball stops) so the distance will be 0.448m
 
Country Boy said:
I have a basic problem with this. A snooker ball primarily rolls with only a slight amount of sliding. The coefficient of friction only applies to the sliding. To answer this you would have to know what part of the motion was sliding and I see no way to determine that.
Thanks! I could work out the solution.
 
I am glad. How did you handle the "rolling versus sliding" problem?
 
Country Boy said:
I am glad. How did you handle the "rolling versus sliding" problem?
I just guessed rolling. Iam still in A levels so probably my textbook doesn't get into so much detail.
 
If there were pure rolling, there would be NO friction!
 
  • #10
Country Boy said:
If there were pure rolling, there would be NO friction!
Yeah you are right.
 
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