Friction and Pulleys

  • #51
2,486
83
I think the top part of the string should be
567.png
 
  • #52
haruspex
Science Advisor
Homework Helper
Insights Author
Gold Member
34,821
6,110
I think the top part of the string should beView attachment 81886
That cannot be string, or the pulley would fall down. Must be a rod.
The upper part of the string runs drom the wall to the pulley. How much longer does that get when the car advances 1m?
 
  • #53
2,486
83
How much longer does that get when the car advances 1m?
Same as distance covered by small block.
 
  • #54
haruspex
Science Advisor
Homework Helper
Insights Author
Gold Member
34,821
6,110
Same as distance covered by small block.
No. Forget the block for the moment, and concentrate on the car, the pulley, the wall, and the length of string from wall to pulley. If the car moves 1m further from the pulley, how much longer is that part of the string?
 
  • #55
2,486
83
How much longer does that get when the car advances 1m?
Total length of string - length of the top part of the string ?
 
  • #56
haruspex
Science Advisor
Homework Helper
Insights Author
Gold Member
34,821
6,110
Total length of string - length of the top part of the string ?
No, I'm asking about that top part of the string, the part that runs horizontally from the wall to the pulley.
 
  • #57
2,486
83
Total length of string -(minus) length of the top part of the string .Right?/QUOTE]
2 PICTURES.png
 
  • #58
2,486
83
Thank you for your patience .
 
  • #59
haruspex
Science Advisor
Homework Helper
Insights Author
Gold Member
34,821
6,110
If the car moves 1m further from the wall, how much further is the pulley from the wall? So how much longer is the piece of string from the wall to the pulley?
 
  • #60
2,486
83
1 meter?
 
  • #61
haruspex
Science Advisor
Homework Helper
Insights Author
Gold Member
34,821
6,110
1 meter?
Right. So what would be the change in length of the lower part of the string, the part that runs from the block to the pulley?
 
  • #62
2,486
83
So what would be the change in length of the lower part of the string
1 meter .
 
  • #65
haruspex
Science Advisor
Homework Helper
Insights Author
Gold Member
34,821
6,110
Shorter?
Right. So how much closer is the block to the pulley?
 
  • #66
2,486
83
So how much closer is the block to the pulley?
1 meter.so distance covered by block is 1 meter,right?
 
  • #67
haruspex
Science Advisor
Homework Helper
Insights Author
Gold Member
34,821
6,110
1 meter.so distance covered by block is 1 meter,right?
It is one metre closer to the pulley. But the pulley has moved how far?
 
  • #69
haruspex
Science Advisor
Homework Helper
Insights Author
Gold Member
34,821
6,110
1 meter?
Right. So the pulley is one metre further from the wall, and the block is one metre closer to the pulley. So how far has the block moved away from the wall?
 
  • Like
Likes gracy
  • #70
2,486
83
So how far has the block moved away from the wall?
1 meter.
 
  • #71
2,486
83
Right. So how much closer is the block to the pulley?
It is one metre closer to the pulley. But the pulley has moved how far?
Right. So the pulley is one metre further from the wall, and the block is one metre closer to the pulley. So how far has the block moved away from the wall?
By all these questions do you want to say that distance covered by car=distance covered by block
 
  • #72
BvU
Science Advisor
Homework Helper
2019 Award
13,670
3,327
No: if the block would NOT be connected to the wall by this wire (and it would NOT move wrt the flat car), THEN the distance covered by the block would be equal to the distance covered by the flat car. So

So the pulley is one metre further from the wall, and the block is one metre closer to the pulley. So how far has the block moved away from the wall?
try again. You have one more attempt left :smile:
 
  • Like
Likes gracy
  • #73
2,486
83
Is my post #70 correct?
 
  • #74
BvU
Science Advisor
Homework Helper
2019 Award
13,670
3,327
As incorrect as #71, since to me these two appear equivalent. The block moves on the car, so distance covered by car ##\ne## distance covered by block
 
  • #75
2,486
83
Distance covered by block would be equal to shorter length of string(the region of string which connects block and pulley).That is block will reach where pulley was.
 

Related Threads on Friction and Pulleys

  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
10
Views
14K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
6
Views
2K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
1
Views
3K
  • Last Post
Replies
1
Views
3K
  • Last Post
Replies
1
Views
3K
Top