(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A 750 kg elevator starts from rest. It moves upward for 3.00 s with constant acceleration until it reaches its cruising speed, 1.75 m/s.

(a) What is the average power of the elevator motor during this period?

(b) How does this power compare with the motor power when the elevator moves at its cruising speed?

Pcruising =

2. Relevant equations

W=Fd

3. The attempt at a solution

(a)

[tex]\sum[/tex]F = T-mg=ma

Vavg=1.75/2 == > a=1.75/2/3

=> T- 750(9.8) = (750)(1.75/2/3)

T=7568.75N

W=T*d

d=Vavg*t=1.75/2*3

W=7568.75*1.75/2*3=19867.97

Am I doing this correctly?

(b) how do I do part b?

I don't think I did part a correctly because I got a much different value... and the internet assignment said I am very close

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Power done by elevator

**Physics Forums | Science Articles, Homework Help, Discussion**