Wednesday
March 22, 2017

Post a New Question

Posted by on Tuesday, January 5, 2010 at 11:33pm.

A student of mass 78 kg wants to walk beyond
the edge of a cliff on a heavy beam of mass
180 kg and length 10 m. The beam is not
attached to the cliff in any way, it simply lays
on the horizontal surface of the clifftop, with
one end sticking out beyond the cliff’s edge:The students want to position the beam so
it sticks out as far as possible beyond the edge,
but he also wants to make sure he can walk to
the beam’s end without falling down.
How far from the edge of the ledge can the
beam extend?
Answer in units of m.

  • Physics!!! :) - , Wednesday, January 6, 2010 at 12:07am

    Summing moments is the key.

    the cg is five ft from the end, so where is the fulcrum (edge of cliff)?

    78*g*d-180g(5-d)=0
    solve for d, the distance the beam overhangs.

  • Physics!!! :) - , Thursday, October 18, 2012 at 12:27pm

    45

  • Physics!!! :) - , Saturday, March 29, 2014 at 3:42pm

    The method posted by bobpursley is wrong

Answer This Question

First Name:
School Subject:
Answer:

Related Questions

More Related Questions

Post a New Question