Elevator starts from rest with constant acceleration

Click For Summary

Homework Help Overview

The problem involves an elevator with a mass of 650 kg that starts from rest and accelerates upward for 3.00 seconds until it reaches a cruising speed of 1.75 m/s. The objective is to determine the average power of the elevator motor during this acceleration phase, with considerations of force and energy principles.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss using kinematic equations to find the height traveled by the elevator and question the relationship between work and power. There is also exploration of using energy equations to find work and whether both methods yield the same result.

Discussion Status

The discussion is active, with participants offering different methods to approach the problem. Some guidance has been provided regarding the use of kinematics and energy equations, but there is no explicit consensus on a single method to solve the problem.

Contextual Notes

Participants note the final time of 3.00 seconds and a calculated distance of 2.63 meters, which are relevant to the discussion of work and energy. There is an emphasis on the need for both final time and distance in the context of kinematics.

splac6996
Messages
37
Reaction score
0

Homework Statement


650kg elevator starts from rest. It moves upward for 3.00s with constant acceleration until it reches its cruising speed of 1.75m/s. What is the average power of the elevator motor during this period?


Homework Equations


use either force or conservation of energy


The Attempt at a Solution


I first used my kinematic equations to find the height which the elevator travels where I am getting stuck is by finding the work to solve for power is it as simple as using w=force*distance
 
Physics news on Phys.org
It is that simple. The force is constant during the acceleration phase. You just have to find it. You already have distance from your kinematics.
 
if I wanted to find work by using energy equation what would that look like. The reason i ask is because I should be able to use that equation as well and get the same answer.
 
I think you do need to do some kinematics. There's lots of ways to go from 0 to 1.75m/sec, all with different power requirements. You need both final time and final distance and the relation between those is kinematics.
 
well I know that my final time is 3.00s and the final distance I found to be 2.63m. But for my energy equation should equal work
 
Ok, then you are all set. You could add the final kinetic energy and final gravitational potential energy to get total work. Or you could work out force and multiply by the distance. Both should give you the same result.
 

Similar threads

  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 31 ·
2
Replies
31
Views
3K
  • · Replies 10 ·
Replies
10
Views
4K
  • · Replies 14 ·
Replies
14
Views
3K
  • · Replies 9 ·
Replies
9
Views
4K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 3 ·
Replies
3
Views
8K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
4
Views
4K
  • · Replies 3 ·
Replies
3
Views
1K