Inclined plane, Calculate friction force

  • #1

Homework Statement



work.jpg


Homework Equations



Wnet = Ek

The Attempt at a Solution



1) That was fine.
2) I just want to confirm if this answer is right?, I got 12.28N. Used work energy theorem.

Sorry for double post, edited the title
 

Answers and Replies

  • #2
haruspex
Science Advisor
Homework Helper
Insights Author
Gold Member
2020 Award
35,265
6,320

Homework Statement



work.jpg


Homework Equations



Wnet = Ek

The Attempt at a Solution



1) That was fine.
2) I just want to confirm if this answer is right?, I got 12.28N. Used work energy theorem.

Sorry for double post, edited the title
Seems a bit high. Pls post your working.
 
  • #3
Seems a bit high. Pls post your working.
Sorry my mistake, forgot something in my calculation. Anyway heres my working

Wnet = Ek
Wg + Wf + Wn = 1/2*m(vf^2 - vi^2)
(5*9.8*sin30*20) - 20Ff + 0 = 1/2*5(12^2 - 6^2)...That 20 is the length of the incline
Ff = 11N.........Now correct?
 
  • #4
haruspex
Science Advisor
Homework Helper
Insights Author
Gold Member
2020 Award
35,265
6,320
Sorry my mistake, forgot something in my calculation. Anyway heres my working

Wnet = Ek
Wg + Wf + Wn = 1/2*m(vf^2 - vi^2)
(5*9.8*sin30*20) - 20Ff + 0 = 1/2*5(12^2 - 6^2)...That 20 is the length of the incline
Ff = 11N.........Now correct?
Yes, that looks right.
 
  • Like
Likes 1 person

Related Threads on Inclined plane, Calculate friction force

  • Last Post
Replies
3
Views
521
  • Last Post
Replies
12
Views
4K
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
11
Views
3K
  • Last Post
Replies
24
Views
3K
Replies
9
Views
2K
Replies
4
Views
6K
Replies
19
Views
21K
  • Last Post
Replies
2
Views
1K
Replies
6
Views
6K
Top