Hydroelectric power. That's just the term for electricity gained by using water, think of a water mill.
Answer:

Explanation:
The frequency of a wave can be found using the following formula.

where <em>f</em> is the frequency, <em>v</em> is the velocity/wave speed, and λ is the wavelength.
The wavelength is 10 meters and the velocity is 200 meters per second.
- 1 m/s can also be written as 1 m*s^-1
Therefore:

Substitute the values into the formula.

Divide and note that the meters (m) will cancel each other out.


- 1 s^-1 is equal to Hertz
- Therefore, our answer of 20 s^-1 is equal to 20 Hz

The frequency of the wave is <u>20 Hertz</u>
<span>Electrical discharge from a charged object
is your answer</span>
When you draw an illustration for this problem, you would come up with the same drawing as shown in the picture. As the hot-air balloon travels upwards, there is a slight time when the bag of sand rises up until it reaches the maximum height. Then, it goes back down to the ground. The total time would be t₁ + t₂. The solution is as follows:
H = v₀²/2g = (2.45)²/2(9.81) = 0.306 m
t₁ = H/v₀ = 0.306 m/2.45 m/s = 0.125 s
t₂ = √2(H + 98.8)/g = √2(0.306+ 98.8)/9.81
t₂ = 4.495 s
Total time = 0.125 s + 4.495 s = 4.62 seconds