Question

A diving board of length 3.00 m is supported at a point 1.00 m from the end, and a diver weighing 520 N stands at the free end. The diving board is of uniform cross section and weighs 295 N.

1) Find the magnitude of the force at the support point.

2) Find the direction of the force at the support point. (upward or downward)

3) Find the magnitude of the force at the left-hand end.

4) Find the direction of the force at the left-hand end. (upward or downward)

Answer 1

As the system is in equilibrium, the force at the support B could be found by taking summation of moments at point M

net moment = 0

0 = - B*1 +295*1.5 + 520*3

B = 2002.5 N

The force at M could be found by either

∑Mв = 0 or ∑Fv = 0

net Fv = 0

0 = -520 - 295 - M + B

M = -815 + 2002.5

M = 1187.5 N

1)

at support

B = 2002.5 N

(2)

direction = upward

(3)

M = 1187.5 N

(4)

downwards