"A fish hangs from a spring scale supported from the roof of an elevator. If the elevator has an upward acceleration of 1.2m/s^2 and the scale reads 200N, under what circumstances will the scale read 150N? What will the scale read if the elevator cable breaks?"

Question

"A fish hangs from a spring scale supported from the roof of an elevator.  If the elevator has an upward acceleration of 1.2m/s^2 and the scale reads 200N, under what circumstances will the scale read 150N?  What will the scale read if the elevator cable breaks?"

There was another part of the question that I had figured out.  The true force of gravity on the fish is 1.8*10^2N.

Damon · Accepted Answer

F = m a
force down on fish = m g
force up on fish = 200
acceleration up =1.2
so
200 - 9.8 m = 1.2 m
11 m = 200
m = (200/11)

then
150 - 9.8(200/11) = (200/11)a

(200/11) (9.8+a) = 150
9.8+a = 8.25
a = -1.55 downward

well if the cable breaks, a = 9.8 dwon
F - 9.8 m = m (-9.8)
F = 0

Stuck · Answer

Thank you for answering both questions! I understand them now.