Answer:
the light will reflect parallel to the principal axis
There are no appropriate units for power on the list you provided
The maximum current in an ac circuit is related to the rms current by:

where

is the rms current and

is the maximum current.
If we re-arrange the formula and we use

, we can find the value of the maximum current:
Answer:
By Newton's third law the cart must then exert an equal and opposite force on the horse. ... If it doesn't accelerate, and it started it rest, it must remain at rest (by the definition of acceleration), and therefore no matter how hard the horse pulls, it can never move the cart