Question

In the following lever system, what is the clockwise torque?

Answer 1

Answer: The total clockwise torque is 900N*m

Explanation: The torque is defined as:

Torque = Force*distance to the axis.

Here there are two torques in opposite directions, if we consider the clockwise direction as the positive one, we have:

T1 = 200N*6m = 1200N*m

T2 = -300N*1m = -300Nm

Where T2 is negative because the torque is anticlockwise.

Another way to think this is to put the zero of our x-axis in the pivot point and say that the x-axis grows to the right. In this model, the distance of T1, is positive 6 meters, and the distance for T2 is negative 1 meter, so the signs match with the ones that we had.

Now we have that the total torque is equal to the sum of all the torques; so:

T = T1 + T2 = 1200N*m - 300N*m = 900N*m

Answer 2

There are two torques here, caused by the force on each end.

Torque = (force) x (distance from the pivot)

Left end: Torque = (300N) x (1m) = 300 N-m counterclockwise

Right end: Torques = (200 N) x (6m) = 1200 N-m clockwise

The net torque is (1200 - 300) = 900 N-m clockwise .