Suppose, in the figure below, a 0.90-m rod experiences a 1.2-T magnetic field and the hand keeps it moving to the right at a constant speed of 3.5 m/s. If the current in the circuit is 0.040 A, what is the average power being delivered to the circuit by the hand?

There is no "figure below".

Average power is the force on the bar multiplied by the velocity.

The force on the bar is B*I*L
L = 0.90 m
B = 1.2 Tesla
I = 0.040 A

To find the average power being delivered to the circuit, we can use the formula:

Average power = Force x velocity

In this case, the force is given by the formula:

Force = current x length x magnetic field

The length of the rod is given as 0.90 m, and the magnetic field is given as 1.2 T. The current is given as 0.040 A.

Substituting these values into the force formula, we get:

Force = 0.040 A x 0.90 m x 1.2 T = 0.0432 N

Now, we can substitute the force and the velocity (3.5 m/s) into the average power formula:

Average power = 0.0432 N x 3.5 m/s = 0.1512 W

Therefore, the average power being delivered to the circuit by the hand is 0.1512 watts.