Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Physics homework help..very appreciated?
A champion weight lifter did 1.10 x 10^4 J of work on a set of barbells weighing 3680N. How much gravitational potential energy did the barbells have at the maximum height of the lift?
please EXPLAIN THOROUGHLY, i am confused and I can't find much help. thanks a ton in advance!
- Dr. ZorroLv 710 years agoFavorite Answer
The work done in lifting a weight mg to a height h equals
W = mg h
We know work (1.10 10^4 J) and force (3680 N), so the height over which he lifted is
W = F h
h = W/F
h = 1.10 10^4 J / (3680 N) = 2.99 m
At that height, the mass of the barbells has potential energy
E = m g h
but this gives 1.10 10^ J again!
To cut a log story short: The work the champion did goes into gravitational potential energy (kinetic energy is zero at the bottom and highest point) . It is just a matter of conservation of energy....
- Anonymous10 years ago
1.1 * 10^4 because all of the kinetic energy would be converted to GPE at the highest point in the lift