There's a lift with a mass of 5600kg and it is currently descending at a speed of -6.4/7. It's a minus because it's decelerating, I've taken down as positive. I've got the answer, but I don't understand it.
The answer is:
Maximum tension = mass x (9.8+(6.4/7))
Maximum tension = 5600 x (75/7)
Maximum tension = 60000
It looks like a force=mass x acceleration equation to me, but why is the weight of the lift not included in the equation? (5600g / 5600 x 9.8 / 54880N).
Why is the 6.4/7 positive when it's accelerating in the opposite direction of gravity?
Edit: The lift is held by a string, it doesn't stretch and it has no weight. Why is the tension in it 60000N?