A 81.5 kg man is riding an escalator in a shopping mall. The escalator moves the man at a constant velocity from the ground level to the floor above, a vertical height of 5.45 m. What is the work done on the man by each of the following forces?
(a) the gravitational force
___J
(b) the escalator
___ J
2007-10-18 06:39:09 · 5 answers · asked by Santina E 1 in Science & Mathematics ➔ Physics
None of the above answers are correct.
Both case are simple to solve. Just use F*d where F=mg
Case A: m=81.5 kg, g=9.81 m/sec^2 and d= -5.45m
(d is negative because the movement was in the direction opposite to the direction of the force)
= 81.5*9.81*-5.45
= -4357 J
Case B is just like A, except that d= 5.45
=4357 J
2007-10-18 07:49:04 · answer #1 · answered by Frst Grade Rocks! Ω 7 · 1⤊ 0⤋
Work done by gravitational force = mgh,
m = 81.5 kg h = 5.45 m
Work done by the elevator = work done by the gravitational force, neglecting frictional & other losses.
2007-10-18 07:03:30 · answer #2 · answered by rabi k 2 · 0⤊ 1⤋
by gravitational force its F=81.5 * 9.8 = 798.7
Word = F * distance = 798.7 * 5.45 = 4352.915
2007-10-18 07:05:55 · answer #3 · answered by ansaritaha007 2 · 0⤊ 1⤋
a gravitational force
2007-10-18 06:42:58 · answer #4 · answered by John C 1 · 0⤊ 2⤋
lol
2007-10-18 06:41:46 · answer #5 · answered by christina 2 · 1⤊ 1⤋