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pinky2468
Nov20-04, 12:18 PM
I am not sure why I am stumped on this problem, but here it is

An escalator 30.0 meters long slants 30degrees relative to the horizontal. If it moves at 1.00m/s at what rate does it do work in lifting a 50kg man from the bottom to the top?

Any suggestions on where to start?

krab
Nov20-04, 12:33 PM
work done in lifting is mgh, so power is time derivative: mg dh/dt. dh/dt is the vertical component of the velocity. Since you have the velocity magnitude and direction, you can figure out the vertical component.

pinky2468
Nov20-04, 12:44 PM
What does the d stand for. Do I need to find the height by using sin 30?

Physics is Phun
Nov20-04, 01:04 PM
I have a feeling you don't know calculus. d stands for derivative or change in. your formula for power is P= mgh/t all you have to do is figure out the height using sin30 with your length and your time with sin30 your speed.