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Dynamics Questions involving Friction

  • #1
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Homework Statement


The coefficient of kinetic friction between a 3.5kg bowling ball and the ice on a frozen lake is very small: μ= 0.02. If the ball is bowled on the ice with an initial velocity of 16.5ms^-1, how far will it travel before friction brings it to rest?

Homework Equations


Fn=mg

The Attempt at a Solution


i have figured out the weight force.
3.5x9.8=34.3N
 

Answers and Replies

  • #2
kuruman
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Hi Nith and welcome to PF.

How is the weight force related to friction?
 
  • #3
haruspex
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The coefficient of kinetic friction between a 3.5kg bowling ball and the ice on a frozen lake is very small: μ= 0.02. If the ball is bowled on the ice with an initial velocity of 16.5ms^-1, how far will it travel before friction brings it to rest?
Are you sure this is the question exactly as given to you?
As it stands it makes no sense. It will slide at first but later roll. No rolling resistance is specified, so it could roll forever.
 
  • #4
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Haruspex it is written exactly like that
And i was just confused and may have thought weight force was needed
 
  • #5
kuruman
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Are you sure this is the question exactly as given to you?
As it stands it makes no sense. It will slide at first but later roll. No rolling resistance is specified, so it will could roll forever.
Because of the sparsity of information I assumed that the ball behaves as if it were a block and slides until it comes to rest.
 
  • #6
haruspex
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Because of the sparsity of information I assumed that the ball behaves as if it were a block and slides until it comes to rest.
It clearly specifies a ball, not a puck.
 
  • #7
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Because of the sparsity of information I assumed that the ball behaves as if it were a block and slides until it comes to rest.
I assume that is what they want. How would you solve this?
 
  • #8
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It clearly specifies a ball, not a puck.
How would you solve this?
 
  • #9
haruspex
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How would you solve this?
As I posted, the question as stated is nonsensical. Two possible errors:
1. They mean a puck, not a ball. In this case, answer @kuruman 's post #2.
2. They meant to ask "before the ball rolls without slipping". In this case, you need to think angular momentum. In what circumstances is that conserved?
 
  • #10
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As I posted, the question as stated is nonsensical. Two possible errors:
1. They mean a puck, not a ball. In this case, answer @kuruman 's post #2.
2. They meant to ask "before the ball rolls without slipping". In this case, you need to think angular momentum. In what circumstances is that conserved?
we have not covered angular momentum. But assuming it is a puck how can i solve it with the given information?
 
  • #11
kuruman
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we have not covered angular momentum. But assuming it is a puck how can i solve it with the given information?
Then answer #2 and see if you can find the acceleration from the force.
 
  • #12
haruspex
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we have not covered angular momentum. But assuming it is a puck how can i solve it with the given information?
You posted one relevant equation. You need one related to kinetic friction. You must have been taught one.
 
  • #13
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You posted one relevant equation. You need one related to kinetic friction. You must have been taught one.
Yes but how do i calculate the disance?
 
  • #14
haruspex
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Yes but how do i calculate the disance?
How do you mean "yes"? Do you mean you know the equation I am referring to? Please post it.
 

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