Work Done by Gravity: Find Magnitude

In summary, the conversation discusses the calculation of work done by a force of gravity on a block that is being pushed up a vertical wall with a constant speed. The block has a mass of 2.52kg and is pushed a distance of 1.54m by a force of magnitude F at an angle of 63.6 degrees with the horizontal. The coefficient of friction is also given. The individual has attempted to use the formula W=mgh, but has been told it is incorrect. They are advised to use the formula W=Fd cos(theta) and look up the specific definition of mgh in their book.
  • #1
AdnamaLeigh
42
0
I'm sick of this stuff

A 2.52kg block is pushed 1.54m up a vertical wall with constant speed by a constant force of magnitude of F applied at 63.6 degrees with the horizontal. The coefficient of friction is .574. Find the magnitude of the work done by the force of gravity.

This is what I did:
W=mgh
W=2.52(-9.8)(1.52)=-38.032J

Apparently it's wrong and I don't understand why. I drew the diagram and the force of gravity is going down.

I already found F=38.648N and the work done by F, 53.265J for a previous problem but I don't think those results will help.
 
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  • #2
Please tell me what mgh is equal to, and you will have solved your problem. (I don't mean the number, I mean look it up in your book and see what its called). :-)
 
  • #3
AdnamaLeigh,
the work, W, done by a force, F, acting on a body while it is displaced through a distance d (a long a straight line), is given by
W = Fd cos(theta)
where theta is the angle between the the force and the displacement. The direction of the force and the displacement does not come into consideration in this calculation of the work.
 

1. What is work done by gravity?

Work done by gravity is the amount of energy transferred when an object is moved by the force of gravity. This force is the result of the gravitational attraction between two objects and is always directed towards the center of mass of the larger object.

2. How is the work done by gravity calculated?

The work done by gravity is calculated by multiplying the force of gravity by the distance the object moves in the direction of the force. This can be represented by the equation W = Fd, where W is the work done, F is the force of gravity, and d is the distance.

3. Is work done by gravity always positive?

No, the work done by gravity can be either positive or negative depending on the direction of the force and the direction of the displacement. If the force and displacement are in the same direction, the work is positive. If they are in opposite directions, the work is negative.

4. How does the mass of an object affect the work done by gravity?

The mass of an object does not affect the work done by gravity. This is because the force of gravity is proportional to the mass of both objects involved in the gravitational interaction. Therefore, the ratio of force to distance (which determines the work done) remains constant regardless of the mass of the object.

5. Can the work done by gravity be converted into other forms of energy?

Yes, the work done by gravity can be converted into other forms of energy, such as kinetic energy or potential energy. This is the basis for many important phenomena, such as the movement of objects falling under gravity or the orbiting of planets around stars.

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