Question

A girl of mass 60 kg tries to balance a man of 90 kg sitting on a sea-saw. If the girl stays 100 cm away from the pivot, at what distance from the pivot should the man be?

A) 100 cm
B) 120 cm
C) 150 cm
D) 200 cm

Answer 1

To balance the seesaw, the torques on both sides of the pivot must be equal. The girl's torque is 6000 kg·cm, and the man's torque is 9000 kg·cm. Therefore, the man should be seated approximately 66.67 cm away from the pivot.

Step-by-step explanation:

The torque is calculated by multiplying the mass of an object by its distance from the pivot. In this case, the girl's torque is 60 kg * 100 cm = 6000 kg·cm, and the man's torque is 90 kg * x = 9000 kg·cm. Since the torques must be equal, we can set up the equation 6000 = 9000, and solve for x:

6000 = 90x

x = 6000 / 90 = 66.67 cm

So, the man should be seated approximately 66.67 cm away from the pivot.