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JeffC
Oct11-04, 06:34 PM
I was doing my homework for my physics class, but now I am stuck at two questions and don't know what to do. :( And I don't know where to start. If someone can get me started and little tips on how-to-solve this question, that'd be awesome! :D

If someone can help me solve this problem, I'd be really greatful! :) And I am glad that I found such a wonderful forum.

Thank you. :)
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An elevator starts from rest with a constant upward acceleration and moves 1min the first 1.9 s. A passenger in the elevator is holding a 4.4 kg bundle at the end of a vertical cord. The acceleration of gravity is 9.8 m=s2 :What is the tension in the cord as the elevator accelerates? Answer in units of N.

NateTG
Oct11-04, 06:52 PM
Can you figure out how fast the elevator is accelerating?

Leong
Oct11-04, 07:48 PM
Use
s=ut+\frac{1}{2}at^2 to find the constant upward acceleration,a.
Use Newton's 2nd Law to find the tension :
T-mg=ma
T=m(a+g)
Upward direction is choosen to be positive, downward direction to be negative.

JeffC
Oct12-04, 07:52 PM
Thank you both of you for answering the question. :)

I actually tried couple of approaches and I discovered Leong's method is the best one and did it. :)

Thanks again for the help!