Kenny and Candy decided to sit on a see-saw while visiting a local play park. Candy, of mass

50 kg, sat 250 cm from the pivot of the seesaw.

(1). Where should Kenny, of 60 kg mass, sit so that a state of stable equilibrium exists?

(ii)

What should Kenny do if he wanted to elevate Candy?

(Acceleration due to gravity = 10 N kg)

(i) 208 cm from the pivot

(ii) Move further from the pivot

Explanation:

(i) Sum of the moments about the pivot of the seesaw is zero.

∑τ = Iα

(50 kg) (10 N/kg) (2.5 m) + (60 kg) (10 N/kg) x = 0

1250 Nm + 600 N x = 0

x = - 2.08 m

Kenny should sit 208 cm on the other side of the pivot.

(ii) To increase the torque, Kenny should move away from the pivot.