Calculate Work Needed to Stop Rolling Cylinder

  • Thread starter Thread starter ViewtifulBeau
  • Start date Start date
  • Tags Tags
    Cylinder Work
Click For Summary

Homework Help Overview

The problem involves calculating the work needed to stop a rolling homogeneous cylinder, considering both its translational and rotational kinetic energy. The subject area includes concepts from dynamics and rotational motion.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • Participants discuss the kinetic energy associated with both the linear motion of the cylinder and its rotational motion. There is an exploration of how to account for both forms of kinetic energy in the work calculation.

Discussion Status

Some participants have attempted calculations involving translational and rotational kinetic energy, but there appears to be confusion regarding the correct approach to combine these energies. Guidance has been offered regarding the need to sum both types of kinetic energy to find the total.

Contextual Notes

Participants are grappling with the definitions and calculations of kinetic energy for both linear and rotational motion, and there may be assumptions about the cylinder's properties that are not fully clarified.

ViewtifulBeau
Messages
50
Reaction score
0
A homogeneous cylinder of radius 30cm and mass 40kg is rolling without slipping along a horizontal floor at 2.4m/s. How much work is needed to stop the cylinder?

work = delta_KE in this case so oi figured .5 *40 * 2.4^2 = 115 J but this is not right, what should i do with the cylinder?
 
Physics news on Phys.org
i still can not figure this one out.
 
Besides KE of the center-of-mass moving in translation (linear),
you also have KE of the extended mass moving AROUND the c.o.m.

KE_rotation = 1/2 I (omega)^2
 
i did this and found omega to be 8 rad/s and I to be 1.8 then i found the KE to be 57.6 this is now right either.
 
"Besides" the old linear KE there's now rotational KE, ALSO.
The total KE is the SUM : KE_linear + KE_rotation
 

Similar threads

Replies
39
Views
4K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 16 ·
Replies
16
Views
3K
Replies
13
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
18
Views
2K
  • · Replies 10 ·
Replies
10
Views
4K
  • · Replies 26 ·
Replies
26
Views
3K
Replies
5
Views
4K