Question

A 0.120 kg, 90.0-cm-long uniform bar has a small 0.055 kg mass glued to its left end and a small 0.110 kg mass glued to the other end. The two small masses can each be treated as point masses. You want to balance this system horizontally on a fulcrum placed just under its center of gravity.

How far from the left end should the fulcrum be placed?

Answer 1

To balance the system, the fulcrum should be placed 0.600 m from the left end of the bar.

Step-by-step explanation:

To balance the system, the torque on the left side of the fulcrum should equal the torque on the right side. The torque is calculated by multiplying the mass by the distance from the fulcrum. Let's denote the position of the fulcrum as x. The torque on the left side would be (0.055 kg) * (x - 0.900 m), and the torque on the right side would be (0.110 kg) * (0.900 m - x). Equating these torques and solving for x, we get:

(0.055 kg) * (x - 0.900 m) = (0.110 kg) * (0.900 m - x)

Simplifying the equation, we find that x = 0.600 m. Therefore, the fulcrum should be placed 0.600 m from the left end of the bar to balance the system.