C: the mechanical energy isn't conserved. Some energy was lost to friction.
Answer:
m = 56.5 kg
Explanation:
Since the addition of mass on one piston caused a change in pressure head at the other. Diameter of the piston calculated is used as 0.46 m
Δm*g / Area = p * g * Δh ..... Eq1


In the above case we can say that power given by external agent to pull the rod must be equal to the power dissipated in the form of heat due to magnetic induction.
Part a)
when we pull the rod with constant speed then power required will be product of force and velocity
here we will have

P = 4 W
v = 4 m/s
now we will have


So external force required will be 1 N
PART B)
now in order to find magnetic field strength we can say

here we know that induced EMF in the wire is E = vBL
so power due to induced magnetic field is given by


by solving above equation we will have

A). balanced force
b). unbalanced force
There's no such thing as either of these. A group of two or more forces can be balanced or unbalanced. A single force can't be.
c). gravitational force ... doesn't cause an object to move in a circle;
Drop a stone from the roof of a tall building and watch it fall.
It goes straight down, not in a circle.
d). centripetal force ... force directed toward the center of a circle,
causes an object to move in a circle.