contestada

A 10 m beam of mass 280 kg extends over a ledge. The beam is not attached, but simply rests on the surface. A 50 kg student intends to position the beam so that he can walk to the end of it. How far from the edge of the ledge can the beam extend?

Respuesta :

Manetho

Answer:

the extension of the beam over the ledge is

x = 4.24 kg  

Explanation:

The length of the beam is L= 10 m

The mass of the beam is M = 280 kg

The mass of the student is m = 50 kg

For the equilibrium the net torque on the beam in

counterclockwise direction about the point of

pivot should be zero.

   Στ = Mg(L/2 - x) - m×g×x = 0

           Mg(L/2 - x) - m×g×x = 0

           Mg(L/2 - x) = m×g×x

           M(L/2 - x) = m×x

           (280 kg)((10 m/2) - x) = (50 kg)(x)

calculating the value of x from the above equation we get

x= 4.24 Kg

the extension of the beam over the ledge is

          x = 4.24 kg  

Otras preguntas