Question

Please read the article below (copy into your address bar, in case you dont undersatnd how internet works):

https://physicsinfootballgrade11bcss.weebly.com/energy-work-power.html

And provide a 250 word summary of the article and how it applies to the concepts of kinetic energy, work, and power. Also provide a description of how to figure kinetic energy, work, and power. If you can provide an additional resource. THIS HAS TO CONTAIN A SUMMARY OF THE ARTICLE AND BE RELATED TO THE ARTICLE OR I WILL NOT THUMBS UP!  If the 250 word summary meets all requirements I will thumbs up promptly.

Answer 1

ENERGY:-
Engineers and scientist realise that there is another more powerfull technique for analyzing motion.And this new concept can be extended to use in other situations like chemical reactions,biological functions etc which does not involve motion.This other technic is "ENERGY".The energy is ability or capacity to do work.But this definition does not extend to chemical or heat energy and some other types of energy so it can be defined precisely as "Energy is a number that we associate with a system of one or more objects and this number changes when state of system changes".

TYPES OF ENERGY:-
Kinetic energy-It is the energy associated with a body with state of motion of object
K.E=1/2mv^2
where m is mass of object and v is speed of object.
so if body is at rest then K.E=0
If body is moving then K.E>0

Gravitational potential energy-It is associated with state of sepration between objects,which attracts each other by gravitational force.
and
U=gravitational potential energy=mgh
here m-mass of object g-acceleration due to gravity h-hight above the earth surface
The potential energy here is due to earth and the object,we have assumed potential energy=0 at surface of earth.
The general definition of potential energy is
"CHANGE IN POTENTIAL ENERGY =-(WORK DONE BY INTERNAL FORCES).
WORK:-
Work W is energy transferred to or from an objectby means of force acting on an object.Energy transferred to object is positive and energy transferred from an object is negative.

W=Fdcos0
where F is force d is displacement and 0 is angle between F and d

Power:- Power is time rate of doing work by a force.
<P>=average power=W/t
P=instantanious power=dw/dt

Mechanical energy-It is sum of kinetic energy and potential energy of an object=U+K
Conservation of energy states that Total amount of energy in this universe is constant or we may say it remain conserved.So energy can neither be created nor be destroyed rather it can change its form.
If W work is done on an object then W=change in mechanical energy+change in thermal energy+change in internal enrgy.
if temperature remains constant during motion and change in internal energy =0 then
W=change in mechanical energy
also if W=0 the change in mechanical energy=0 so Ui+Ki=Uf+Kf this is called conservation of mechanical energy
so if work done by external agent =0 then mechanical energy remain conserved.