Question

what will happen if on a see -saw a child gets up suddenly? why?

Answer 1

The other child would rapidly fall to the ground below his side of the seesaw. It is the counter-balanced forces of gravity (on each child, on each side) that lets the seesaw rock up and down in a gentle manner.

Answer 2

Heya friend!
Rajdeep here....

Suppose two children are sitting on either sides of a seesaw. A seesaw works on the principle of lever, i.e., Load x Load Arm = Effort x Effort arm, or Moment of load about the fulcrum = Moment of effort about the fulcrum.

So, if a child gets up suddenly and the load (child) at the other side remains sitting, then the seesaw arm on which the other child is sitting, will turn down, as his weight will act on the arm of the seesaw, and there will be no other force to balance the seesaw (bring it in equilibrium position).

Hope my answer is satisfactory...

Thanks!!