Elevator Tension With Upward Acceleration

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Homework Help Overview

The problem involves calculating the tension in a cable supporting an elevator that is accelerating upward. The elevator's weight is given, along with the acceleration value, and participants are exploring the relationship between these forces.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the application of Newton's second law (F=ma) and the forces acting on the elevator, including weight and tension. There are attempts to calculate mass and net force, as well as questions about the direction of forces and how they interact during upward acceleration.

Discussion Status

The discussion is ongoing, with participants providing insights into the forces involved and checking assumptions about the calculations. Some guidance has been offered regarding the relationship between tension and gravitational force, but no consensus has been reached on the final tension value.

Contextual Notes

Participants are working within the constraints of a homework problem, which may limit the information available for discussion. There is also a focus on ensuring the correct interpretation of forces acting on the elevator.

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Homework Statement



An elevator weighing 10 000N is supported by a steel cable. Determine the tension in the cable when the elevator is accelerated upward at 3.0 m/s2


A) 7.0kN
B) 10.0 kN
C)11.6 kN
D) 13.1 kN
E) 40.0 kN

Homework Equations



F=ma W=mg (g=9.8m/s^2)

The Attempt at a Solution


W=mg
10 000=m(9.8)
m=1020
 
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The net force (i.e. the total of all the forces) is what causes acceleration in the equation F=ma. So draw a diagram and label the forces acting on it. (Gravity and Tension) so now use the F=ma equation and plug everything in and off you go.
 
So it would be
W=mg
10 000=m(9.8)
m=1020

F=ma
F=1020(3)
F=3060

3060+10 000 = F
F= 13.1 kN?
 
Remember that the force of gravity is opposite the force of tension. One's up and one's down.
 
So the 3060 would be subtracted from the elevators weight because it's accelerating upwards (against gravity) making it 7000?
 
Oh my goodness, I'm sorry, you were right in the first place, I read it wrong. Good work! Sorry to confuse.
 

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