Question

he 3.2 kgkg, uniform, horizontal rod in (Figure 1) is seen from the side. Figure 1 of 1The figure shows a 100 centimeters horizontal bar with a dot on it, at the distance of 25 centimeters from its left end.

Part A What is the gravitational torque about the point shown? Express your answer with the appropriate units.

Answer 1

The situation can be visualized as

The linear mass density of the rod is

The mass of the left side of the beam is therefore

And the mass of the right side of the beam is

The masses can be assumed to be concentrated in the middle of their respective sides as shown in the figure.

Now, the torque at the given point can be calculated using (taking counterclockwise positive)

Putting values in SI units (distances in m)

So, the net torque about the given point is -7.84 N.m.

NOTE: The magnitude is 7.84 N.m.