The speed of the rock at 20 m is 34.3 m/s
Explanation:
We can solve this problem by using the law of conservation of energy: the mechanical energy of the rock, sum of its potential energy + its kinetic energy) must be conserved in absence of air resistance. So we can write:
where
:
is the initial potential energy
is the initial kinetic energy
is the final potential energy
is the final kinetic energy
The equation can also be rewritten as follows:
where:
m = 100 kg is the mass of the rock
is the acceleration of gravity
is the initial height
u = 0 is the initial speed (the rock starts at rest)
is the final height of the rock
v is the final speed when h = 20 m
And solving for v, we find:

Learn more about kinetic energy and potential energy here:
brainly.com/question/6536722
brainly.com/question/1198647
brainly.com/question/10770261
#LearnwithBrainly
Answer:
I literally just learned this last week and if I remember correctly it is Faraday's Law of Induction.
Explanation: Hope this helps also I hope you have/had an amazing day today<3
Im not really sure about this im stuck to
Under water turbans that are placed at the above to middle of the ocean they are used to capture kinetic motion