Newton's Laws, Kinematics, and Friction

  • #1

Homework Statement



A student pushes horizontally northward on a 1.5 KG textbook initially at rest. The book is located 1.0m from the edge of a long table. the coefficient of static friction is 0.25, and the coefficient of kinect friction is 0.20. The applied force is just enough to get the book to start moving and is maintained for 1.5 seconds after the motion has begun.

B) Determine the Applied force (Fa) of the student to get the book moving

Homework Equations



Fnet = Fa + Ff
Fnet = mass* acceleration
|Fnormal| = |Fgravity| = |mass* g|

The Attempt at a Solution



I'm able to figure out that the normal force is 14.7 N, and that the force of friction is -3.675 N, (letting force against movement be negative). I'm just not sure how much force should be applied if it's "just enough to get the book to start moving"?

Any help would be greatly appreciated
:smile:
 

Answers and Replies

  • #2
157
0
What they mean by "just enough to get the book moving" is a force essentially equal to overcome the force of friction for the static scenario. So the force of friction that you calculated already.
 

Related Threads on Newton's Laws, Kinematics, and Friction

  • Last Post
Replies
17
Views
3K
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
2
Views
7K
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
5
Views
2K
  • Last Post
Replies
16
Views
8K
  • Last Post
Replies
16
Views
3K
  • Last Post
Replies
1
Views
3K
  • Last Post
Replies
3
Views
5K
  • Last Post
Replies
2
Views
5K
Top