Calculating Work on a Sliding Block on an Inclined Plane

In summary, the conversation discusses finding the total work done on a block on a frictionless inclined plane, as well as the work done by the force of gravity. The work energy theorem is mentioned and the equations for finding the work by both the force going up the ramp and gravity are provided. There is also a mention of a possible error in inputting the equation for work done by gravity.
  • #1
danni7070
92
0

Homework Statement


A block of weight w sits on a frictionless inclined plane, which makes an angle (theta) with respect to the horizontal. A force of magnitude F, applied parallel to the incline, pulls the block up the plane at constant speed.

1)The block moves a distance up the incline. The block does not stop after moving this distance but continues to move with constant speed. What is the total work Wtot done on the block by all forces? (Include only the work done after the block has started moving, not the work needed to start the block moving from rest.)

2)What is Wg, the work done on the block by the force of gravity as the block moves a distance up the incline?

Homework Equations



Wtot = the sum of all work factors right ? So I have to find the work from the force going up the ramp, the work from gravity. ??


The Attempt at a Solution



I think the answer to q1 is W-tot = FL + (-wsin(theta))+N (The opposite force of mg = w)

But this is not correct but I don't know why?

Anyone?
 
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  • #2
For the total work, what does the work energy theorem say?

for work done by gravity, use work = [tex]\vec{F}\cdot\vec{d}[/tex]
 
  • #3
love how i got Wgravity wrong...


Wf= -mgcos(theta) * L

(from masteringphysics, your answer is off by a multiplactive factor..)
 
  • #4
guslergusler said:
love how i got Wgravity wrong...


Wf= -mgcos(theta) * L

(from masteringphysics, your answer is off by a multiplactive factor..)

Wf is work by the force F?

Wf = mgsin(theta)*L

F must be mgsin(theta) acting up the plane.
 
  • #5
sorry i meant force done by gravity
 
  • #6
guslergusler said:
sorry i meant force done by gravity

work done by gravity is -mgsin(theta)*L
 
  • #7
that's exactly what i put...

but masteringphysics says I'm off by a multiplactive factor,,
 
  • #8
guslergusler said:
that's exactly what i put...

but masteringphysics says I'm off by a multiplactive factor,,

hmmm... did you put in -wsin(theta)*L exactly?
 
  • #9
thank you

my fault ... i input -wgsin(theta)*L
 
  • #10
guslergusler said:
thank you

my fault ... i input -wgsin(theta)*L

no prob.
 

1. What is work on a sliding block?

Work on a sliding block refers to the amount of energy required to move a block along a surface with friction. It is a measure of the force applied over a distance.

2. How is work on a sliding block calculated?

The work on a sliding block is calculated by multiplying the force applied to the block by the distance it moves in the direction of the force. The formula for work is W = F * d, where W is work, F is force, and d is distance.

3. What factors affect the work on a sliding block?

The factors that affect the work on a sliding block include the mass of the block, the coefficient of friction between the block and the surface, and the distance the block is moved.

4. How is friction involved in work on a sliding block?

Friction is the force that opposes the motion of the block along the surface. It is responsible for the energy lost as heat during the movement of the block and therefore affects the amount of work required.

5. What are some real-life applications of work on a sliding block?

Work on a sliding block has many real-life applications, such as pushing a heavy object across the floor, pulling a sled through the snow, or pushing a shopping cart through a store. It is also an important concept in engineering and mechanics for designing and understanding the movement of objects.

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