Finding gravitational potential energy

In summary, the distance between the sixth and eleventh floors of a building is 30.0m with a combined mass of 1350 kg for the elevator and its contents. To find the gravitational potential energy of the elevator at the eighth floor relative to the sixth floor, we can use the equation E=mgh. However, we must also consider the work formula of W=F"d and the force acting in the opposite direction, which can be calculated using W=F"d cos 180'. After applying these equations, the gravitational potential energy is found to be 1.5x10^5 J, which is the same as the answer in the back of the textbook.
  • #1
jaron
23
0

Homework Statement


The distance between the sixth and the eleventh floors of a building is 30.0m. The combined mass of the elevator and its contents is 1350 kg.

a) find the gravitational potential energy of the elevator when it stops at the eighth floor, relative to the sixth floor.

(the answer in the back of my textbook is : 1.5x10^5 J )

Homework Equations


now i am thinking E=mgh, but i am also thinking that i an going to need to do something about the work formula. i know that w=F"d, and when the force is acting in the opposite direction, you must use W=F"d cos 180'. but this might be totally irrelevant.


The Attempt at a Solution


with this equation i am getting: E=1350(9.81)(30) E=397305 J
 
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  • #2
The distance between the 6th and 11th is 30 meters.

The distance between the 6th and 8th then is 12 meters isn't it?
 
  • #3
yeah, thanks. i feel like an idiot about the question now..
forgot to consider that fact that the 30m was for the whole height and not for floor 6-8.
 

FAQ: Finding gravitational potential energy

1. What is gravitational potential energy?

Gravitational potential energy is the energy that an object possesses due to its position in a gravitational field. It is the potential for an object to do work as a result of its position relative to other objects in the field.

2. How is gravitational potential energy calculated?

The gravitational potential energy of an object is calculated by multiplying the object's mass by the acceleration due to gravity (9.8 m/s^2) and the height of the object above a reference point (usually the ground). The formula is PE = mgh, where PE is the potential energy, m is the mass, g is the acceleration due to gravity, and h is the height.

3. What are some examples of objects with gravitational potential energy?

Objects that are lifted or raised above the ground have gravitational potential energy, such as a book on a shelf, a tree branch, or a roller coaster at the top of a hill. Planets, moons, and other celestial bodies also have gravitational potential energy due to their position in the gravitational field of larger objects like stars.

4. How does gravitational potential energy relate to kinetic energy?

Gravitational potential energy and kinetic energy are both forms of mechanical energy. As an object falls, its potential energy decreases while its kinetic energy increases. At the bottom of its fall, all of the potential energy is converted into kinetic energy. The relationship between the two can be described by the law of conservation of energy, which states that energy cannot be created or destroyed, only transferred from one form to another.

5. How is gravitational potential energy used in everyday life?

Gravitational potential energy is used in many everyday activities, such as using a swing, riding a roller coaster, or lifting objects. It is also a crucial concept in fields such as engineering, physics, and astronomy, where understanding and calculating potential energy is important for designing structures, predicting the motion of objects, and studying celestial bodies.

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