(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A lamp hangs vertically from a cord in a descending elevator that decelerates at 1.6 m/s2. (a) If the tension in the cord is 92 N, what is the lamp's mass? (b) What is the cord's tension when the elevator ascends with an upward acceleration of 1.6 m/s2?

2. Relevant equations

F=ma

3. The attempt at a solution

a) using M for mass, so as not to confuse it with 'm' for meters

F(net)=M*a, T-F(gravity) = M*a

92N - M*(9.8 * m/s^2) = M*(-1.6 * m/s^2)

9.8*M - 1.6 M = 92 kg

M = 11 kg

b)

T - (11 kg)*(9.8 m/s^2) = (11 kg)*(1.6 m/s^2)

T = 18N + 110N

T = 128N

Both of my answers are wrong. Where am I going wrong in my thought process?

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# Homework Help: Lamp Hanging in an Elevator

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