Static friction between two bodies and a surface

Click For Summary

Homework Help Overview

The discussion revolves around the mechanics of static friction between two boxes, where box A rests on top of box B, which is on a surface. The original poster expresses confusion regarding the maximum force that can be applied to box B without causing box A to slip off. The problem involves understanding the forces of static friction acting between the boxes and the surface, and how these forces interact when a force is applied to box B.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants explore the logic behind the calculations presented in the textbook, questioning the relationship between the applied force, static friction, and the resulting accelerations of the boxes. There is a focus on understanding how static friction operates and the implications of applying different forces to box B.

Discussion Status

Participants are actively engaging with the problem, offering insights and corrections to each other's reasoning. Some have clarified the role of static friction in relation to the applied forces, while others are still grappling with the implications of these forces on the motion of the boxes. There is a recognition of the complexity of the situation, with ongoing attempts to reconcile different interpretations of the mechanics involved.

Contextual Notes

There are discussions about the maximum static friction values and how they relate to the forces acting on the boxes. Participants are considering the effects of acceleration and the conditions under which slipping occurs, as well as the transition from static to kinetic friction when box B begins to move.

  • #31
nothing is wrong, at least not from where I'm sitting.

in fact I received back a quiz I had 2 days ago, and got 100(A+ in conventional terms, I guess).

Doc Al has been great help in helping me understand it all.

thanks again.
 
Physics news on Phys.org
  • #32
the answer given by ur textbook is correct
u can solve the problem if u know seudo force topic
 
  • #33
if u want the block A to be stationary with respect to bolck B.
the net force acting on it must be equal to zero.
fmax a,b = 40
a = 40/5=8
now a seudo opp in direction to this frictional force should act to keep it in rest.
so the block B must move with accelaration of 8
on bolck B frictional force 20N is acting back.
F - fmaxa,b = ma
F- 20 = 160
f = 180N
any doubt contact <personal email removed>
i will explain through a diagram
 
Last edited by a moderator:

Similar threads

  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 6 ·
Replies
6
Views
2K
Replies
4
Views
1K
  • · Replies 15 ·
Replies
15
Views
1K
Replies
16
Views
3K
  • · Replies 42 ·
2
Replies
42
Views
4K
Replies
6
Views
2K
  • · Replies 1 ·
Replies
1
Views
4K
Replies
13
Views
2K
  • · Replies 3 ·
Replies
3
Views
7K