What Is the Self-Locking Angle for a Block on a Steel Tabletop?

  • Thread starter Thread starter jumpyroo92
  • Start date Start date
  • Tags Tags
    Friction
Click For Summary
SUMMARY

The discussion focuses on determining the self-locking angle for a block on a steel tabletop, specifically involving a 10kg block with a 3kg block on top. The coefficient of friction (u) is given as 0.7. To find the angle at which the middle block self-locks, it is essential to analyze the forces acting on both blocks using the equations of motion and friction. The self-locking angle is reached when the applied force equals the maximum static friction force, resulting in an infinite force requirement to slide the block.

PREREQUISITES
  • Understanding of Newton's second law (F=ma)
  • Knowledge of frictional forces (Ffr=uFn)
  • Ability to draw and interpret free-body diagrams
  • Familiarity with static and kinetic friction concepts
NEXT STEPS
  • Calculate the net force acting on the blocks using F=ma
  • Explore the implications of different angles on frictional forces
  • Study the effects of varying the coefficient of friction on self-locking angles
  • Learn about static versus kinetic friction in practical applications
USEFUL FOR

Students in physics or engineering courses, educators teaching mechanics, and anyone interested in understanding friction and motion dynamics in practical scenarios.

jumpyroo92
Messages
3
Reaction score
0

Homework Statement


A 10kg block sits on a steel tabletop. A 3kg block sits on the first block. A string connects the top block to the table.

a) If the string makes an angle of 10 degrees with the horizontal, how much force is required to move the middle block?

b) At what angle will the block "self lock" (an infinite force is required to slide the middle block)?

u=0.7

Homework Equations



F=ma

Ffr=uFn

Fnet(first block)= Fapp-(Ffr+Ffr) ?

The Attempt at a Solution



I really have no idea.

I don't get the self lock thing at all.
 
Physics news on Phys.org
Sketch the problem first : table, block, the other block on top, string.
Draw the free-body diagram for both blocks.

ehild
 

Similar threads

Calculating Acceleration of M1,M2 System w/ Friction
  • · Replies 10 ·
Replies
10
Views
4K
Block on an incline and frictional force
  • · Replies 9 ·
Replies
9
Views
14K
What is the relationship between tension and mass in a system with friction?
  • · Replies 6 ·
Replies
6
Views
2K
A problem about friction with three blocks stacked together
  • · Replies 5 ·
Replies
5
Views
4K
Finding the time it takes for two stacked blocks to travel
  • · Replies 18 ·
Replies
18
Views
3K
Deriving motion equations for two blocks on a rough table
  • · Replies 11 ·
Replies
11
Views
3K
How Does Friction Affect the Acceleration and Tension in a Two-Block System?
  • · Replies 9 ·
Replies
9
Views
3K
Friction problem involving a block and pulley on a ramp....
  • · Replies 2 ·
Replies
2
Views
3K
Acceleration of a block on a moving wedge
  • · Replies 6 ·
Replies
6
Views
3K
Three-mass System with Friction
  • · Replies 4 ·
Replies
4
Views
6K