Understanding Gravitational Potential Energy: 3 Questions Answered

[yyttr2]

I have three questions here, and I am a bit confused about what "relative to" means in this context:

1."A 1.91 kg ball is attached to a ceiling by a
3.28 m long string. The height of the room is
5.94 m .
The acceleration of gravity is 9.8 m/s2 .
What is the gravitational potential energy
associated with the ball relative to the ceiling?
Answer in units of J."
2. "What is its gravitational potential energy rel-
ative to the floor?
Answer in units of J."

3."What is its gravitational potential energy rel-
ative to a point at the same elevation as the
ball?
Answer in units of J."



I'm not looking for specific answers, I just need help interpreting the questions.

 

[brno17]

I have three questions here, and I am a bit confused about what "relative to" means in this context:

1."A 1.91 kg ball is attached to a ceiling by a
3.28 m long string. The height of the room is
5.94 m .
The acceleration of gravity is 9.8 m/s2 .
What is the gravitational potential energy
associated with the ball relative to the ceiling?
Answer in units of J."
2. "What is its gravitational potential energy rel-
ative to the floor?
Answer in units of J."

3."What is its gravitational potential energy rel-
ative to a point at the same elevation as the
ball?
Answer in units of J."



I'm not looking for specific answers, I just need help interpreting the questions.

Relative to ceiling means the distance from ceiling to the core of earth. (r + distance) r=radius of earth

Relative to floor means distance from floor to core of Earth (r + distance)

Relative to same point shuld be (r + balls height)

Im not sure its not very clear but that's how I understand it.

 

[Dale]

I have three questions here, and I am a bit confused about what "relative to" means in this context:

1."A 1.91 kg ball is attached to a ceiling by a
3.28 m long string. The height of the room is
5.94 m .
The acceleration of gravity is 9.8 m/s2 .
What is the gravitational potential energy
associated with the ball relative to the ceiling?
Answer in units of J."
2. "What is its gravitational potential energy rel-
ative to the floor?
Answer in units of J."

3."What is its gravitational potential energy rel-
ative to a point at the same elevation as the
ball?
Answer in units of J."



I'm not looking for specific answers, I just need help interpreting the questions.

When you measure gravitational potential energy you use the formula E=mgh. But you are free to choose which height you consider to be h=0. When they say "relative to the floor" they mean use the floor as h=0.