The diagram below shows a beam of length 20.0 m and mass 40.0 kg resting on two supports placed at 5.0 m from each end.
A person of mass 50.0kg stands on the beam between the supports. The reaction forces at the supports are shown.
(a) State the value of N1 + N2
(b) The person now moves toward the X end of the beam to the position where the beam just begins to tip and reaction force N1 becomes zero as the beam starts to leave the left support. Determine the distance of the girl from the end X when the beam is about to tip.