Calculating Gravitational Potential Energy for a Sliding Box: Expert Tips

In summary, the question involves finding the gravitational potential energy change for a box sliding down a slope with given weight, kinetic coefficient of friction and angle. The vertical height can be calculated using the slant height and angle, and the change in potential energy can be determined by using the formula mgh. The final part of the question also involves calculating the work done by gravity and friction, as well as the speed and change in potential energy of the box.
  • #1
avb203796
63
0
How would you find the gravitational potenetial energy change for a box being slide down a slope? The weight of the box is 490N, the kinetic coefficient of friction is 0.12N, the slant of the slope is 45 degrees. I knwo how to find the forces acting ont he boxes and have calculated all of them but I have no clue how to solve for the potential energy. Please help!
 
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  • #2
change in gravitational potential energy of a body of mass m is mgh, where h is the vertical height between the two positions.
 
  • #3
but given just an angle how would I know the height?
 
  • #4
are you sure that's all the information you've been given?
 
  • #5
1. The vertical height should be given.
2. They may give the slant height and with that and the angle known we can calculate the vertical height.

Just check again the question otherwise it is not possible to caclculat the change in KE with given data.
 
  • #6
THis was thwe actual complete question but I am just trying to solve the last part:

A 50.0 kg crate slides down a slope of 45 degrees for a distance of 200.0m. how much work will be done by gravity? How much work will be done by friction, if the kinetic coefficent of friction is 0.12? What speed will it attain at this point if it was originally at rest? By how much will its gravitaional potential energy change during the slide?

Again I have solve all of the problem except for the last question.
 
  • #7
here
the distance covered is given 200m
hence the vertical height fallen is 200 sin 45deg. = 2000*707 = 141.4 m.
now you can calculate mgh
remember the height is lost means the potential energy decreases(may be the answer is having a negative sign)
 
  • #8
How did you solve the question1?
Please show your method. I am asking avb - others don't reply.
 
  • #9
the distance covered down the slope is given = 200m hence the vertical component of this distance is 200 sin45deg. = 200*0.707
mgh is the loss in potential energy.(_ve)
 
  • #10
I solved for the weight which was 490N, then I multiplied the weight times the 200m distance times cos(45degrees). y?
 
  • #11
Ok thank you mukundpa!
 
  • #12
Just think o the coincidence of the first question with the last one. I think you should know the relation between energy and work. What is the definition of energy? So you anyway solved it before posting?
 
  • #13
ya you may solve it in that way too if you have calculated the speed at the end
loss in potential energy = gain in KE + work done against friction
 

1. What is potential energy?

Potential energy is the energy that an object possesses due to its position or configuration. It is stored energy that can be converted into other forms of energy, such as kinetic energy, when the object moves or changes its position.

2. What are some examples of potential energy?

Some examples of potential energy include a raised object, a stretched rubber band, a compressed spring, and a charged battery. In each of these examples, the object has the potential to do work or change its position due to its stored energy.

3. How is potential energy calculated?

The amount of potential energy an object possesses is calculated using the formula PE = mgh, where PE is potential energy, m is the mass of the object, g is the acceleration due to gravity, and h is the height or distance from the ground. The unit for potential energy is joules (J).

4. What is the relationship between potential energy and kinetic energy?

Potential energy and kinetic energy are two forms of energy that are interrelated. When an object has potential energy, it has the ability to do work and move. When the object moves, potential energy is converted into kinetic energy, which is the energy of motion. The two forms of energy can be converted back and forth depending on the object's position or speed.

5. How can potential energy be increased or decreased?

Potential energy can be increased by increasing an object's mass or its height from the ground. It can also be increased by stretching or compressing an object, such as a spring. Conversely, potential energy can be decreased by decreasing an object's mass or height, or by releasing the stretched or compressed object.

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