Answer:

Explanation:
From the question we are told that:
Height
Length
Mass 
Final speed
Generally the equation for Potential Energy P.E is mathematically given by

Therefore
Initial potential energy

Generally the equation for Kinetic Energy K.E is mathematically given by

Therefore
Final kinetic energy

Generally the equation for Work_done is mathematically given by

Therefore


Answer:
The answer would be A. The waves that heat a cup of water in a microwave oven
Physics
Chemistry
Physical science is science which studies non-living things.This covers things on earth to the universe.The main branches are physics and chemistry.The other sub-branches are Astronomy, meteorology and Geology.Physics is concerned with the basic principals of matter and energy.It covers concepts in motion, energy, force, pressure , light and many other areas we encounter in our day to day life.Chemistry is concerned with composition of matter and how it reacts.Material in chemistry is understood through observing molecules, atoms, elements and their interaction in nature including their properties.Chemistry is further divided into organic chemistry and natural chemistry sub-branches.
Hope this helps you!!!
Answer:
0.3m
Explanation:
Given parameters;
Elastic energy = 20J
Spring constant = 445N/m
Unknown
Final extension of the spring = ?
Solution:
The elastic potential energy of a stretched spring can be determined using the expression below;
EP =
k e²
k is the spring constant
e is the extension
Insert the parameters and solve;
20 =
x 445 x e²
multiply those sides by 2;
2(20) = 445e²
40 = 445e²
e² =
= 0.09
e = √0.09 = 0.3m