• Support PF! Buy your school textbooks, materials and every day products Here!

Finding acceleration

  • Thread starter Bdurb
  • Start date
  • #1
5
0
Chuck pulls his brother in a sled. Chucks brother and the sled have a combined mass of 50kg. On a flat surface, chuck pulls with 120 N 30 degrees above the horizontal. The coefficient of friction btwn the sled and the snow is .08. Find the acceleration of the sled.



i drew my FBD
DSC01211.jpg


but im not sure if assumed wrong for the Fn or the normal force. Any help is greatly appreciated.
 

Answers and Replies

  • #2
thrill3rnit3
Gold Member
713
1
Normal forces always acts perpendicular to the surface.

And that 500 should be a 50, based from your question.
 
  • #3
Redbelly98
Staff Emeritus
Science Advisor
Homework Helper
Insights Author
12,100
129
Chuck pulls his brother in a sled. Chucks brother and the sled have a combined mass of 50kg. On a flat surface, chuck pulls with 120 N 30 degrees above the horizontal. The coefficient of friction btwn the sled and the snow is .08. Find the acceleration of the sled.

i drew my FBD
http://i746.photobucket.com/albums/xx109/SubyFTW/DSC01211.jpg

but im not sure if assumed wrong for the Fn or the normal force. Any help is greatly appreciated.
Your Fn is incorrect. Fn must act straight upward, perpendicular to the surface as thrill3rnit3 said.

Set up two equations using Fnet=ma. One equation for the y-direction, and one for the x-direction.

Normal forces always acts perpendicular to the surface.

And that 500 should be a 50, based from your question.
No, the 500 is correct since he is indicating forces in Newtons.

Using g=10 m/s2 gives a weight of 500 N for the 50 kg mass.
 
  • #4
thrill3rnit3
Gold Member
713
1
Oops, brain fart that time :tongue:
 

Related Threads on Finding acceleration

  • Last Post
Replies
8
Views
2K
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
3
Views
1K
  • Last Post
Replies
4
Views
4K
  • Last Post
Replies
4
Views
1K
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
4
Views
453
  • Last Post
Replies
5
Views
1K
  • Last Post
Replies
5
Views
1K
  • Last Post
Replies
0
Views
743
Top