Answer:
a. 
b. 
Explanation:
Using the triangle theorem both triangle the woman makes between the light so the rate of change of length can use geometry first

Solve to find the rate relation


Now the rate of the change rate


Finally the rate of her shadow moving


It's Endorphins. That's a pain killer produced by the brain.
Its tangential speed is constant although its velocity is changing. As the object changes direction, it results in a changing of positive and negative signs of the velocity. Although, the magnitude of the velocity (speed) is not changing.
The total work done by the electric field on the charge is given by the scalar product between the electric force acting on the charge and the displacement of the charge:

where the force is F=qE, d=0.556 and

. Using the value of q and E given by the problem, we find