Answer:
- <u>77.8 m/s, downward</u>
Explanation:
For uniform acceleration motion, the average speed is equal to half the soum of the initial velocity, Vi, and the final velocity, Vf
- Average speed = (Vf + Vi)/2
Also, by definition, the average speed is the distance divided by the time:
- Average speed = distance / time
Then:
Other kinematic equation for uniform acceleration is:
Since the window is falling and the air resistance is ignored, a = g (gravitational acceleration ≈ 9.8m/s²)
Replacing the known values we can set a system of two equations:
From (Vf + Vi)/2 = 300m/6.62s
(Vf + Vi) = 2 × 300m/6.62s
- Vf + Vi = 90.634 equation 1
From Vf = Vi + a×t
Vf - Vi = 9.8 (6.62)
- Vf - Vi = 64.876 equation 2
Adding the two equations:
- Vf = 77.8 m/s downward (velocities must be reported with their directions)
The mechanical energy in the falling water is used to spin the generator, and gets transformed into electrical energy. That's the first choice on the list.
I would say the last option, since with an increase in temperature, water molecules will speed up.
The answer would be B, George Darwin :)
Water will evaporate from any
water source and life forms. The answer is letter C. An application of heat
into water will cause the water to evaporate. This is because the
intermolecular forces of attraction of water can be broken by sufficient energy
application.