Block, Ramp, Friction, and Spring

Click For Summary

Homework Help Overview

The problem involves a block being pulled up an incline with friction, followed by its motion on a frictionless surface and interaction with a spring. The subject area includes mechanics, specifically work-energy principles and dynamics on inclined planes.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the work done by the man pulling the block and the kinetic energy involved when the block reaches the horizontal surface. There is an attempt to relate potential energy and kinetic energy while considering friction. Questions arise regarding the details of the problem setup, particularly the mention of the spring and the angle of the incline.

Discussion Status

The discussion is ongoing, with participants clarifying aspects of the problem and questioning the inclusion of certain elements, such as the spring. Some participants are exploring the relationships between energy forms and forces acting on the block.

Contextual Notes

There is some confusion regarding the details provided in the problem, specifically the angle of the incline and the role of the spring. Participants are working with the assumption that the incline angle is 29°, but there are mixed interpretations of the problem's requirements.

r34racer01
Messages
62
Reaction score
0
A man pulls a block of mass m = 20 kg up an incline at a slow constant velocity for a distance of d = 3.5 m. The incline makes an angle q = 29° with the horizontal. The coefficient of kinetic friction between the block and the inclined plane is µk = 0.3.

a) What is the work Wm done by the man? Wm = 513.1

At the top of the incline, the string breaks and the block, assumed to be at rest when the string breaks, slides down a distance d = 3.5 m before it reaches a frictionless horizontal surface. A spring is mounted horizontally on the frictionless surface with one end attached to a wall. The block hits the spring, compresses it a distance L = 0.6 m, then rebounds back from the spring, retraces its path along the horizontal surface, and climbs up the incline.

b) What is the speed v of the block when it first reaches the horizontal surface? v = 3.91
c) What is the spring constant k of the spring? k = 849.3
d) How far up the incline d1 does the block rebound? d1 = ?

For picture: https://wug-s.physics.uiuc.edu/cgi/courses/shell/common/showme.pl?cc/DuPage/phys2111/fall/homework/Ch-08-GPE-ME/block_ramp_friction_spring/9.gif
W = ΔKE, W = F*d, U = m*g*h

So I'm stuck on part d.). I thought I could do U = KE - W(friction) = (((1/2)m*v^2) - μmgh*cos(29)) / mg = 0.517 but that didn't work. Any help please?
 
Last edited by a moderator:
Physics news on Phys.org
There is no mention of spring in the problem. How is that?
 
rl.bhat said:
There is no mention of spring in the problem. How is that?

Sorry my bad, I've added the rest of the info after part a.), I've also added a link to the picture included.
 
Angle of the inclined plane is not given. Whether d is the displacement along the inclined plane?
 
rl.bhat said:
Angle of the inclined plane is not given. Whether d is the displacement along the inclined plane?

Yes it is.

The incline makes an angle q = 29° with the horizontal.
 
While going up the kinetic energy of the block = work done against (frictional force + component of weight in the downward direction) + PE.
 

Similar threads

  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 18 ·
Replies
18
Views
5K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 15 ·
Replies
15
Views
4K
  • · Replies 7 ·
Replies
7
Views
6K
Replies
1
Views
3K
  • · Replies 1 ·
Replies
1
Views
5K
  • · Replies 1 ·
Replies
1
Views
3K