Pull over the side and stop until it passes you. (my opinion)
The motion of the stone consists of two separate motions: in air, with average speed

, and in the water, with average speed

.
The total distance covered is 127 m, and it is the sum of the distances covered in air and in the water:

(1)
and the total time taken is the sum of the time the stone travels in air + the time the stone travels in the water:

Since

, we can rewrite (1) as

We have now a system of 2 equations with 2 unknown variables:

And if we solve it, we find


Which means that the stone travels for 7 seconds in air and for 5 seconds in the water.
Given that,
Initial velocity , Vi = 0
Final velocity , Vf = 40 m/s
Acceleration due to gravity , a = 9.81 m/s²
Distance can be calculated as,
2as = Vf² - Vi²
2 * 9.81 *s = 40² - 0²
s = 81.55 m
For half height, that is, s = 40.77m
Vf= ??
2as = Vf² - Vi²
2 * 9.81 * 40.77 = Vf² - 0²
Vf² = 800
Vf = 28.28 m/s
Therefore, speed of roller coaster when height is half of its starting point will be 28 m/s.
Aw, I hate physics, is this on Apex?
Resistance can be calculated with the information given in the question.
Equation for Resistance: R = V/I
V (voltage) = 200 Volts
I (current) = 200 Amps
So 200 divided by 200 = freaking 1
Answer: R = 1 (ohms)
Hope this Helps!