Finding work and the Change in Thermal Energy

Click For Summary

Homework Help Overview

The problem involves calculating the work done by a force while pulling a sled and determining the change in thermal energy due to friction. The context is set in a physics scenario involving forces, friction, and energy transfer.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the need to incorporate the applied force into the work equation and question the relationship between work and thermal energy. There are inquiries about the sled's acceleration and the relevance of a free body diagram.

Discussion Status

Some participants have provided calculations for the work done and have begun exploring the relationship between work and thermal energy. Guidance has been offered regarding the connection between frictional work and thermal energy.

Contextual Notes

There is mention of the coefficient of kinetic friction and the angle of the applied force, which may influence the calculations. The discussion reflects uncertainty about the sled's acceleration and the implications for energy changes.

alyssad

Homework Statement


Kerry is pulling a 156-kg sled along a snowy, horizontal path with a 620-N force directed at an angle of 29.0° above the ground. He pulls the sled over a distance of 26.0 m, and the coefficient of kinetic friction between the sled and the ground is 0.0622.

I need to find the amount of work that Kerry does as he pulls the sled AND I need to find the increase in thermal energy.

Homework Equations


I know that
W = μkmgΔr*cos(Θ)
ΔEth = FkΔr

The Attempt at a Solution


I'm not really sure where to begin with finding the answer. I feel like the work equation needs to include the force that is given in the problem statement. And I would appreciate help with the thermal energy part as well.

Thank you!
 
Physics news on Phys.org
alyssad said:

Homework Statement


Kerry is pulling a 156-kg sled along a snowy, horizontal path with a 620-N force directed at an angle of 29.0° above the ground. He pulls the sled over a distance of 26.0 m, and the coefficient of kinetic friction between the sled and the ground is 0.0622.

I need to find the amount of work that Kerry does as he pulls the sled AND I need to find the increase in thermal energy.

Homework Equations


I know that
W = μkmgΔr*cos(Θ)
ΔEth = FkΔr

The Attempt at a Solution


I'm not really sure where to begin with finding the answer. I feel like the work equation needs to include the force that is given in the problem statement. And I would appreciate help with the thermal energy part as well.

Thank you!
Have you drawn a free body diagram?
 
Chestermiller said:
Have you drawn a free body diagram?
I have drawn a free body diagram. I'm pretty sure that the equation I posted is the equation for the amount of work needed to overcome the force of friction. I still don't know where to go from here.
 
Is the sled accelerating, such that its kinetic energy is increasing?
 
So I found that W = 14098 J, and I know that is the correct answer. How should I start finding the change in thermal energy?
 
The change in thermal energy is equal to the frictional work.
 

Similar threads

Calculating Work and Change in Thermal Energy
  • · Replies 2 ·
Replies
2
Views
2K
Pulling an object at an angle with friction -- find the Kinetic Energy
  • · Replies 6 ·
Replies
6
Views
4K
What's the coefficient of kinetic friction?
  • · Replies 8 ·
Replies
8
Views
4K
Need help with finding thermal and Kinetic energy
  • · Replies 20 ·
Replies
20
Views
2K
Thermal energy dissipated from the brakes in a car
  • · Replies 28 ·
Replies
28
Views
3K
Kinetic Energy and Newton Forces - distance/speed
  • · Replies 3 ·
Replies
3
Views
2K
Work and Kinetic Energy of a Sled
  • · Replies 4 ·
Replies
4
Views
5K
Work done during a collision -- Change in Kinetic Energy & change in Momentum
  • · Replies 1 ·
Replies
1
Views
2K
How Does Angling the Force Affect Kinetic Energy Increase in a Sled?
  • · Replies 9 ·
Replies
9
Views
3K
How Much Work Is Done When Pulling a Sled at an Angle?
  • · Replies 3 ·
Replies
3
Views
2K