weight(force) = mg
Ep = mgh
work = force*distance
You found the work, which is just ∆Ep
work and energy are the same units.
what work is done in raising a 3.0 kg mass from a 2.5 m high ledge to a 6.5 m high shelf?
How much potential energy (Ep) does the mass now posses?
Ok so for part 1 its w = m g h
w = (3.0kg)(10m/s^2)(6.5m-2.5m)
w = 120J
now how do you find the potential energy?
2 answers
All yo can really find in this world is DIFFERENCES in potential energy.
In this case, whoever wrote the question probably expected you to define zero potential at the FLOOR
so the h you use for part 1 which is 6.5 -2.5 = 4
is NOT the h you use for part 2
for part 2, use the full height of 6.5 meters
The question is trying to be tricky, but in fact is poorly worded.
In this case, whoever wrote the question probably expected you to define zero potential at the FLOOR
so the h you use for part 1 which is 6.5 -2.5 = 4
is NOT the h you use for part 2
for part 2, use the full height of 6.5 meters
The question is trying to be tricky, but in fact is poorly worded.
1 answer