Physics!!! :)

posted by .

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!!! :) -

    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!!! :) -

    45

  • Physics!!! :) -

    The method posted by bobpursley is wrong

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Physics - Torque

    A student of mas 70kg wants to walk beyond the edge of a cliff on a heavy beam of mass 300kg and length 10m. The beam is not attached to the cliff in any way, it simply lays on the horizontal surface of the cliff top, with one end …
  2. Physics

    A beam of mass mb = 10.0 kg, is suspended from the ceiling by a single rope. It has a mass of m2 = 40.0 kg attached at one end and an unknown mass m1 attached at the other. The beam has a length of L = 3 m, it is in static equilibrium, …
  3. physics

    A gymnast with mass m1 = 47 kg is on a balance beam that sits on (but is not attached to) two supports. The beam has a mass m2 = 118 kg and length L = 5 m. Each support is 1/3 of the way from each end. Initially the gymnast stands …
  4. physics

    A gymnast with mass m1 = 47 kg is on a balance beam that sits on (but is not attached to) two supports. The beam has a mass m2 = 118 kg and length L = 5 m. Each support is 1/3 of the way from each end. Initially the gymnast stands …
  5. physics

    In Fig. 12-51, uniform beams A and B are attached to a wall with hinges and loosely bolted together. Beam A has length LA = 2.55 m and mass 49.0 kg; beam B has mass 69.0 kg. The two hinge points are separated by distance d = 1.86 m. …
  6. Physics

    A 3.0m long uniform beam of mass 24kg hangs off the edge of a building with 2.5m in the air, as shown in the diagram. A bucket of bolts of mass 30.kg rests on the board over the building at a distance of 10.cm from the edge of the …
  7. Physics

    A purple beam is hinged to a wall to hold up a blue sign. The beam has a mass of mb = 6.1 kg and the sign has a mass of ms = 16.4 kg. The length of the beam is L = 2.83 m. The sign is attached at the very end of the beam, but the horizontal …
  8. physics

    You are a sucker for scenic overlooks, so you want to build a house overhanging a cliff. The way you do this is by taking a 20,000 N concrete beam and hang it over the edge of the cliff with one edge at the cliff ledge and the other …
  9. Physics

    A purple beam is hinged to a wall to hold up a blue sign. The beam has a mass of mb = 6.7 kg and the sign has a mass of ms = 17.4 kg. The length of the beam is L = 2.83 m. The sign is attached at the very end of the beam, but the horizontal …
  10. Physics

    A purple beam is hinged to a wall to hold up a blue sign. The beam has a mass of mb = 6.7 kg and the sign has a mass of ms = 17.4 kg. The length of the beam is L = 2.83 m. The sign is attached at the very end of the beam, but the horizontal …

More Similar Questions