Physics -------- force and work question?

Question

Karen has a mass of 57.0kg and she rides up the escalator. Karen rode a distance of 65m. How much work did the escalator do on Karen if it has an inclination of 30 degrees?

The answer is 1.8 x 10^4 Joules. But I don't know how to arrive at it.

Answer 1

The escalator is doing work against gravity, so it only matters how much height she gains. So find her change in height:

( 65 meters ) ( sin 30 degrees ) = 32.5 meters.

Then the work done is m g h = ( 57.0 kg ) ( 9.8 m/s² ) ( 32.5 m ) = 1.8 x 10^4 Joules.