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Man In Elevator Problem

  • Thread starter Cole07
  • Start date
  • #1
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Force Of Man On Elevator

Homework Statement



An 65- kg man stands in an elevator. What force does he exert on the floor of the elevator under the following conditions? The elevator is stationary.
Answer:637.65N

The elevator accelerates upward at 2.3 m/s2.
Answer:787.15N

The elevator rises with constant velocity of 3.1 m/s.

While going up, the elevator accelerates downward at 1.7 m/s2.
Answer:527.15N

The elevator goes down with constant velocity of 6.3 m/s.

Homework Equations


EF=0


The Attempt at a Solution



so far i have the ones where i allready have the acceleration but i don'tknow how to do the ones with velocity because i don't have a t(time) i thought maybe i could do the same and multiply 3.1m/s*65kg which is 201.5 and then use the formula EF=0 so EF=0=-201.5-637.65 which equals 839.15 but this was wrong, could you just give me an idea on how to get started and help would be greatly appreciated.
 
Last edited:

Answers and Replies

  • #2
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Do I not have enough work swown?
 
  • #3
PhanthomJay
Science Advisor
Homework Helper
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Do I not have enough work swown?
you need only to look at newton's first law to arrive at a solution. What is the acceleration of the elevator and person when they are moving at constant speed?
 
  • #4
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how do i get to the acceleration when i don't have anything but weight and velocity?
 
  • #5
106
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i have figured it out thank you for your help.
 

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