Question

A 15 kg television sits on a shelf at a height of 0.3 m. How much gravitational potential energy is added to the television when it is lifted to a shelf of height 1.0 m?

How do I calculate this? I really just need to know the equation or something. It's on earth obviously, so use earths gravitational energy.

Answer 1

Alright so tell me what you know about potential energy. :)

Answer 2

I honestly don't know much. I do know that the equation for this question should be Gravitational Potential Energy = (Height from ground) * (acceleration of gravity) * (mass of object).
But I can't figure out how to substitute in earth's acceleration of gravity correctly.

Answer 3

How do you mean substitute correctly? You mean when the units are involved?

Answer 4

like..
The acceleration should be 9.8 meter/sec^2. I can't figure out how to put that in the equation?
also, i'll brb.

Answer 5

and I'm back :3

Answer 6

Same I was away too. Right, so in the equation U=mhg, the g or acceleration must always be in m/s^2. So you would just put 9.8 into the equation :)

Answer 7

I tried that! It said I had the wrong answer. That's why I was confused.

Answer 8

Alright can you show me what you did? Note: it is asking for the potential ADDED. So the potential after minus the potential before :)

Answer 9

okay, so what I did is this:

0.3 * 9.8 * 15 = 44.1 J

the correct answer was 102.9 J

Answer 10

oh wow.

Answer 11

totally missed that whole difference thing.

Answer 12

Should have been 0.7 * 9.8 * 15. -_-

Answer 13

Ok so what you did there is finding the potential before it was moved higher. Yup you're almost there. Just get the potential for at the higher position and minus the one at the lower position :)

Answer 14

Of you could do that :D

Answer 15

Haha, thanks for helping me notice my mistake ;) This is obviously me just not reading well enough into the questions.. I'll make sure I do that next time. Thanks for your help!

Answer 16

No problem. I should have asked in the beginning if you noticed that.