Question

The strength of a beam varies inversely as the cube of its length. The beam 3m long can support 920 kg. how much can a similar 7m beam ?

Answer 1

This is not the physics portion :/

Answer 2

Let me link you- http://openstudy.com/study#/groups/Physics

Answer 3

Close both os them up now.

Answer 4

This is a fine algebra problem.

Strength Varies inversely with Length MEANS

\(Strength = \dfrac{k}{Length}\)

We are given

\(920\;kg = \dfrac{k}{3\;m}\)

Solve for 'k' and you are almost done.