how much work is done when a 63.8 kg person climbs a flight of stairs 10.2m high at constant speed?

Question

anonymous · Answer

W=FD

amistre64 · Answer

|dw:1316718367117:dw|

jamesj · Answer

Work here = change in potential energy = mgh

anonymous · Answer

okay...so distance is 10.2...how do we get force?

jamesj · Answer

The force is the gravitational force, mg

anonymous · Answer

mass x gravity?

anonymous · Answer

does gravity get set as -9.81 or positive?

jamesj · Answer

Well, regardless of what sign convention you use, we know the person has to have done positive work

amistre64 · Answer

$$\int_{0}^{10.2}63.8\  dh$$

anonymous · Answer

6383.9556 J?

amistre64 · Answer

650.76 kg-m , convert it to joules if you want to

amistre64 · Answer

if i see it right

anonymous · Answer

well its a multiple choice question and all answers are in joules....closest answer is 6380 J

amistre64 · Answer

i dont know the conversion ratio ... so i cant really see if thats a good option or not

jamesj · Answer

A Joule is in kg.m^2/s^2.

In the equation change in potential energy = m g h
If m is in kg
g units is m/s^2
and h units is m
We're good.

m = 63.8 kg
g = 9.8 m/s^2  (simplifying)
h = 10.2 m

So mgh = 6,377 J