Answer:
49.5 Hz.
Explanation:
From the question given above, the following data were obtained:
Period (T) = 0.0202 s
Frequency (f) =?
The frequency and period of a wave are related according to the following equation:
Frequency (f) = 1 / period (T)
f = 1/T
With the above formula, we can obtain the frequency of the wave as follow:
Period (T) = 0.0202 s
Frequency (f) =?
f = 1/T
f = 1/0.0202
f = 49.5 Hz
Therefore the frequency of the wave is 49.5 Hz.
Answer:

Explanation:
We are given that
Potential difference=V=154 V
Surface charge density=
Using 
We know that


Where

Using the formula


Using 
Hence, the spacing between the plates=
Answer: 100lbs
Explanation: The Earth pushes you down at 100lbs, so you push down the earth by 100lbs which is enough to keep you firmly attached to the ground and not allow you to jump more than a couple of feet.
1 Is advantage because with out is. you couldn't carry the piano at all.
2 Efficiency because it is going against you.