So I don't need to negate the acceleration even though it's decelerating, because it's not an actual force vector acting upon the lamp? I removed the (-) and my answer is correct now (thank you!), but I just want to understand the 'why' so I can not make this mistake again.
In part a) the elevator is decelerating downwards, so I made it negative. In part b) the elevator is accelerating upwards, so I made it positive. My thought process was:
Upwards (positive) vectors:
Tension T
Downwards (negative) vectors:
M*Gravity
acceleration = 1.6 (part b only)...
Homework Statement
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?
Homework...