PDA

View Full Version : Elevator Question


gr3g1
Nov2-05, 04:35 PM
If a man weights 50kg, but a scale in the elevator says he is 300N, what can you say about the acceleration?

Thanks a lot

verty
Nov2-05, 04:53 PM
What does a scale measure? What is it measuring in this question? What would a scale tell you on the moon?

gr3g1
Nov2-05, 04:57 PM
The scale is weighing how heavy he is in newtons

Integral
Nov2-05, 04:58 PM
More correctly, he has a mass of 50kg. Weight is in Newtons. What is his weight in Newtons?

ZapperZ
Nov2-05, 04:59 PM
If the man is 50kg, what would be his weight (W = mg) if the elevator is not moving, for example? Now compare this with what the scale is reading, and apply your experience by remembering what you felt the last time you were on an elevator.

Zz.

gr3g1
Nov2-05, 05:02 PM
w = ma
300 = 50(a)

a = 6 m/s^2?

verty
Nov2-05, 05:06 PM
Acceleration is a vector...

gr3g1
Nov2-05, 05:08 PM
6ms^2 upwards?

verty
Nov2-05, 05:10 PM
It almost seems you are just looking for answers. Figure out the answer.

gr3g1
Nov2-05, 05:11 PM
I am, because it was a question on my test!

verty
Nov2-05, 05:46 PM
It doesn't help to know an answer without understanding it. All the information is in this thread. Read through it again and try to understand.

Integral
Nov2-05, 06:17 PM
w = ma
300 = 50(a)

a = 6 m/s^2?

Where did you get that value of a?