Angular accelaration problem help

Click For Summary
SUMMARY

The discussion focuses on calculating the time at which a penny begins to slip on a record player due to angular acceleration. Given an angular acceleration of α = 20.0 rad/s² and a coefficient of static friction (μ) of 0.500, the penny will slip when the centrifugal force exceeds the frictional force. The frictional force is calculated as F_friction = μmg, while the centrifugal force is F_centrifugal = mw²r. By solving the equation μmg = mw²r, the angular velocity (w) at which slipping occurs can be determined, followed by calculating the time (t) using the relationship w = αt.

PREREQUISITES
  • Understanding of angular acceleration and its units (rad/s²)
  • Knowledge of static friction and its coefficient
  • Familiarity with centrifugal force calculations
  • Basic algebra for solving equations
NEXT STEPS
  • Study the relationship between angular velocity and angular acceleration
  • Learn about the principles of static friction in rotational motion
  • Explore the concept of centrifugal force in non-inertial reference frames
  • Investigate real-world applications of angular acceleration in mechanical systems
USEFUL FOR

Physics students, mechanical engineers, and anyone interested in the dynamics of rotational motion and frictional forces.

alexito01
Messages
5
Reaction score
0
A penny rests on a record at a radius r=0.200m. The record player is turned on and the record steadily accelerates with angular acceleration alpha=20.0 rad/s^2. The coefficient of static friction between the record and the penny is 0.500. At what time will the penny begin to slip?
 
Physics news on Phys.org
Basically the penny will begin to slip when the centrifugal force is greater than the frictional force.
Your frictional force is Umg where U is the coefficient of friction(0.5) in this case.
Ur centrifugal force will be mw^2r where w is the angular velocity.

solve for Umg=mw^2r first to get w at which it slips...

then use w=angular accel* t to get ur t
 

Similar threads

  • · Replies 17 ·
Replies
17
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 12 ·
Replies
12
Views
2K
Replies
5
Views
2K
  • · Replies 42 ·
2
Replies
42
Views
4K
Replies
3
Views
2K
Replies
3
Views
2K
  • · Replies 9 ·
Replies
9
Views
3K