Max height crate can be dropped before breaking

[Myriadi]

Homework Statement

A 40kg crate is lifted by a poorly working hoist system that risks dropping the object, which breaks at forces exceeding 1000N. Find the maximum height to which the crate can be hoisted before it risks breaking if dropped.

Homework Equations

F=ma=mg
U=mgh=(mv^2)/2
Fd=U

The Attempt at a Solution

Yes, it's a bizarre question... I honestly have no idea how to approach this.

This is all I could think of:

Fd=mgh
1000*d=40*9.81*h

But isn't d equal to h? How does that work?

I can't really seem to get anywhere with this...

 

[mgb_phys]

You don't have enough information. It's not the rate of falling that matters - it's the rate of stopping at the bottom

 

[Myriadi]

But would we not just assume that the crate stops instantaneously?

 

[Pengwuino]

But would we not just assume that the crate stops instantaneously?

The force would then be infinite. Remember, F = dp/dt. More information is needed for the problem.

 

[Myriadi]

Ah, I understand here. Thank you. Problem solved... err not really, but the topic can be closed.