Question

Determine whether quantities vary directly or inversely and find the constant of variation. Levon, who weighs 153 lb, sits 6 ft from the seesaw support. How far from the support should sit Sonya, whose weight is 102 lb, if she wants to balance the seesaw?

Answer 1

The weight times the distance has to equal for it to balance. So Sonya, who weights only two-thirds as much .as Levon (102/153=2/3), has to sit 3/2 times as far, or 6*3/2=9 feet. 3/2 or 1.5 would be the constant of variation 9*102=6*153=918 on both sides. The heavier you are, the closer you need to sit, so they would vary inversely.

Answer 2

The question should be about type 1 lever of physic. In type 1 lever, there is two object/force with the fulcrum located between it. The force made by the object weight is influenced by the distance to the fulcrum. Longer distance/moment arm will result in a higher force. The calculation for balanced force would be:

force1 * distance1 = force2* distance2
153 lb *g * 6ft= 102lb * g * distance2
distance2= 153* 6ft /102 = 9ft