Help for physics static and kinetic friction

  • #1
sundeepsingh
8
0
help for physics static and kinetic friction.
Question:
A 70 Newtons Penguin is on a 50 N. sled. the static friction between the penguin and sled is 0.671 and the kinetic friction between the sled and the SNOW is 0.119. FInd the maximum horizontal force that can be applied without the penguin sliding off the sled?
plz post the answer A.S.A.p
 

Answers and Replies

  • #2
Doc Al
Mentor
45,433
1,886
Please post your work to get help.

Hint: What is the maximum value of the static friction that the sled can exert on the penguin? What acceleration is associated with that force? Apply Newton's 2nd law to find the applied force on the sled.
 
  • #3
sundeepsingh
8
0
this is what i did.
the friction force between sled and snow is= FN X u=(70.1+50)*0.119=14.2919 N.
the friction force between the penguin and sled = (70.1)*0.671=47.0371, therefore, the max horizontal force that can be applied to the sled without causing the penguin to slide off the sled=14.2919+47.0371=61.329 N. But this is wrong, where m i wrong plz tell me.
 
  • #4
Pengwuino
Gold Member
5,124
17
Did someone say penguin :D
 
  • #5
Doc Al
Mentor
45,433
1,886
sundeepsingh said:
the friction force between sled and snow is= FN X u=(70.1+50)*0.119=14.2919 N.
OK. (But the penguin weighs 70N, not 70.1N.)
the friction force between the penguin and sled = (70.1)*0.671=47.0371,
OK. (Same comment.)
therefore, the max horizontal force that can be applied to the sled without causing the penguin to slide off the sled=14.2919+47.0371=61.329 N.
Nope. First find the maximum acceleration of the penguin. (What force acts on the penguin?) Then figure out what force must be applied to the sled so that the sled+penguin has that acceleration. (Don't forget to consider the friction force between sled and snow that must be overcome.)
 
  • #6
sundeepsingh
8
0
THANKS a lot DOC AL, i LUV U lol :P
 

Suggested for: Help for physics static and kinetic friction

Replies
6
Views
377
Replies
6
Views
476
  • Last Post
Replies
20
Views
567
Replies
5
Views
663
  • Last Post
Replies
5
Views
362
Replies
7
Views
341
Replies
9
Views
533
Replies
10
Views
989
Top