Force question on elevator cable

AI Thread Summary
To determine the force exerted by the cable on a 700 kg elevator accelerating upwards at 3 m/s², the net force (Fnet) is calculated using Fnet = ma, resulting in 2,100 N. The gravitational force (Fg) acting on the elevator is 7,000 N. The tension (T) in the cable is then found by combining these forces, leading to T = Fnet + Fg, which totals 9,100 N. Clarification is provided that Fnet represents the sum of all forces, and the correct labeling of variables is emphasized. The discussion concludes with an acknowledgment of improved understanding regarding the forces involved.
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A 700 kg elevator suspended by a cable accelerates upwards at 3 m/s^2. The force exerted by the cable on the elevator is?
(use g=10 m/s^2)

m=700 kg
a= 3.0 m/s^2

Fnet= 700 kg * 3.0 m/s^2
= 2,100.0 N Upward force

Fnet= 700 kg * 10 m/s^2
= 7,000.0 N Downward force

Fnet= 2,100.0 N + 7,000.0 N = 9,100.0 N

So is 9,100.0 N the total force exerted on the cable?
 
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Yes, but you didn't express that very well. All of those different numbers can't be Fnet. One of them is Fnet=ma, one of them is gravitational force and one is the cable tension. Can you label them correctly?
 
Fnet= 700 kg * 3 m/s^2
= 2,100.0 N

Fg= 700 kg * 10 m/s^2
= 7,000.0 N

T= 2,100.0 N + 7,000.0 N
= 9,100.0 N

What is the variable for tension. I am not sure so I just used T.
Would this be a more suitable answer?
 
Better. Fnet is the sum of all forces. Fnet=T-Fg. So yes, T=Fnet+Fg.
 
Thanks a lot. Appreciate your help.
 
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