Question

4. The drawing below shows Alex and his daughter Florence playing on a see-saw. Alex has a mass of 90 kg, Florence has a mass of 30 kg and she is sitting 1.8 m from the pivot.

a) Find out at what distance from the pivot should Alex sit in order to balance the see-saw.

b) What would happen to Florence if Alex moves closer to the pivot than the equilibrium position. Explain your answer.

c) what are the two conditions of equilibrium?

Answer 1

a) Required distance = 30×1.8/90 m

= 0.6m

b) The see saw will be tilted upwards on the Alex's side and downwards on the Florence's side.

c) Conditions for equilibrium require that the sum of all external forces acting on the body(i.e. the see saw) is zero (first condition of equilibrium), and the sum of all external torques from external forces is zero (second condition of equilibrium).

Answer 2

$\huge\underline\mathcal\purple{BTS}$

$\huge\underline\mathcal\green{EXO}$