Question

An escalator carries 20 passengers of average mass of 60 kg. It travels 4.2 m in height in 1 minute each floor. What is the minimum power for the escalator to lift these passengers from the first floor to the third floor? (Take g = m / s^2)

Answer 1

P= 840 W

Explanation:

The question is quite confuse
however, the work you done is like the potential energy that the system gains:
`W = mgh`
i suppose `g = 10m/s^2`; if different you can do again the calcules
`W = (20 xx 60 kg) xx 10 m/s^2 xx 4,2 m =50400 J`
Power is the work divided the time that it takes
`P= W/t= (50400 J) /(60 s)= 840 W`
if you go from the firt floor to the third foor, it increases the work, but also the time increases and the Power is the same