Question

Two girls are sitting on the same side of a see-saw. One girl is 28 kg and sitting 2.4 m away from the middle. The other girl is 35 kg and 2.6 m away from the middle. Their dad can balance them out if he sits 2.0 m away from the middle on the other side. What is their dad's mass?

Answer 1

Their dad's mass is = 79.1 kg

Answer 2

how did you get it?

Answer 3

Here is the diagram-

Answer 4

what is the formula ?

Answer 5

Now just use the principle of moments - Total anticlockwise force from Center of Gravity =

Mass of 1st girl X Distance from middle + Mass of 2 nd girl X Distance from middle..

Daddy counterbalances the forces .. thus, anticlockwise moment force = clockwise..

Daddy is sitting at 2m from the middle on the other side, Thus =

(Mass of 1st girl X Distance from middle + Mass of 2 nd girl X Distance from middle)/2

Gives us daddy's mass. :)

Answer 6

oh is see :) THANKS .. can you answer the other one ? :)

Answer 7

Sure..