How Does an Inclined Plane Affect Mechanical Energy and Work?

Click For Summary
SUMMARY

The discussion focuses on the mechanics of a block being pulled up an inclined plane, analyzing the relationship between mechanical energy, work, and forces involved. Key equations include the change in mechanical energy (ΔE) equating to the work done by non-conservative forces (Wnoncons) and the work done by gravity (Wgrav) being equal to the negative change in potential energy (ΔPE). The role of friction is highlighted, with the work done against it calculated as W = μ * m * g * cos(θ). The total work done on the block (Wtot) is confirmed to equal the change in kinetic energy (ΔKE).

PREREQUISITES
  • Understanding of basic mechanics principles, including potential energy (PE) and kinetic energy (KE).
  • Familiarity with inclined planes and the concept of angles in physics.
  • Knowledge of non-conservative forces, particularly friction.
  • Ability to apply work-energy principles in mechanical systems.
NEXT STEPS
  • Study the work-energy theorem and its applications in mechanical systems.
  • Learn about the effects of friction on inclined planes and how to calculate it.
  • Explore gravitational potential energy calculations in various scenarios.
  • Investigate the relationship between work done by conservative and non-conservative forces.
USEFUL FOR

Students of physics, mechanical engineers, and anyone interested in understanding the principles of work and energy in mechanical systems involving inclined planes.

bobbob
Messages
1
Reaction score
0
A block of mass M is being puled up an inclined plane at a constant speed, by an attached rope that exerts a tension T. The block is pulled a distance L. The plane makes an angle theta with the horizontal, and the coefficient of kinetic friction between the block and the incline is uk.

a) Let E=PE + KE of the block. What is the change in the mechanical energy E of the block? What is the change in the potential energy of the block?

b) Verify that deltaE = Wnoncons, the change in the mechanical energy of the block is equal to the work done by the non-conservative forces acting on the block.

c) what is the Wgrav, the work done by gravity on the block? Check that Wgrav = -delta PE.

d) Combining your results find the total work done on the block, Wtot = Wcons + Wnoncons.
Verify that Wtot = delta KE

any help would be much appreciated..not sure how to do this part. thanks
 
Physics news on Phys.org
Welcome to PF.

Start with a) then. The block moves at constant speed, so what is the Δ in KE? It moves L, at an angle of θ, so how much higher does it get after moving L? What does that make the Δ in PE of gravity?

For the rest of it, what is the non-conservative force? Friction? And the work to friction is what? W = F*d = μ *m*g*cosθ ?
 

Similar threads

Variable friction on an inclined plane and maximum velocity
  • · Replies 33 ·
2
Replies
33
Views
4K
Calculating Work and Kinetic Energy on an Inclined Plane
  • · Replies 2 ·
Replies
2
Views
3K
Conservation of Energy Along an Incline with Friction
  • · Replies 3 ·
Replies
3
Views
2K
What is the displacement of a 3.0 kg block sliding down an inclined plane?
  • · Replies 12 ·
Replies
12
Views
2K
Distance of box pushed up incline by spring
  • · Replies 1 ·
Replies
1
Views
3K
How Does Friction Affect Motion on an Inclined Plane?
  • · Replies 3 ·
Replies
3
Views
1K
Inclined Plane Forces - with a twist
  • · Replies 2 ·
Replies
2
Views
1K
Block attached to a cord on an inclined plane
  • · Replies 1 ·
Replies
1
Views
1K
Work-Energy Theorem and Friction
  • · Replies 9 ·
Replies
9
Views
4K
What Is the Work Done by Normal Reaction Forces on an Inclined Plane System?
  • · Replies 13 ·
Replies
13
Views
4K