Question

Kinetic and Potential Energy

An object with a massof 100 grams (0.100 kg) is dropped from a certain height and has a velocity of 60 meters/second. If the potential energy of this object is 179.99 joules, how high was the object when it was dropped?

a) 9.2 x 10^1 meters
b) 1.8 x 10^2 meters
c) 9.8 x 10^2 meters
d) 1.0 x 10^2 meters

Answer 1

if i calculate height i get 183 m , which is obviously wrong compared to the choices available, but B is the only answer that is close to mine.

Answer 2

Do you know a formula I can use?

Answer 3

well you mentioned one very important clue in your question

Answer 4

Potential energy

Answer 5

to calculate PE you must now the mass of an object and height and also factor in the gravitation.

Answer 6

Ep = potential energy; m = mass; g = gravity(9.8m/s); h = height
Ep = mgh

i know in some countries they use the value 10m/s for gravity.

Answer 7

what i've basically done is use the Ep formula because the height variable is in it, and just reversed it

Answer 8

hope that helps a bit

Answer 9

what formula were you using?

Answer 10

B