# Teeter-Totter Problem

1. Dec 3, 2007

### odie5533

1. The problem statement, all variables and given/known data
Suppose that a heavy person and a light person are balanced on a teeter-totter made of a plank of wood. Each person now moves toward the fulcrum a distance of 25 cms. What effect will this have on the balance of the teeter-totter?
A) The heavy person's end will go down
B) The teeter-totter will remain in balance
C) The light person's end will go down
D) One cannot tell whether either end will rise or fall without knowing the relative mass of the plank
E) Only if the plank has significant mass will the light person's end go down

3. The attempt at a solution
Since the teeter-totter is initially in balance, the center of gravity is right on the fulcrum. When they move in, the lighter person's end will go down since being that it is in balance they are at different distances from the fulcrum. The lighter person, being farther away, will have a greater effect than the closer heavier person, so C, the lighter person's end will go down.

I'm not at all sure if this is right

2. Dec 3, 2007

### PhanthomJay

Yes, correct.