Answer:
An apple hanging at a branch has potential energy due its position. It can be written as PE= mgh where m is the mass of the apple h is the distance between the apple and the ground and g is the acceleration due to gravity.
as the apple falls from the tree it loses its potential energy and gains kinetic energy due to the movement of the apple. Its kinetic energy will be given by KE= 1/2mv² where m is the mass of the apple and v is the speed with which the apple falls.
As the apple falls the height or the distance reduces and PE becomes reduces. But it gains Kinetic energy due to its speed.
But when the apple falls to the ground and comes to rest its kinetic energy is converted to potential energy.
thus the total energy remains the same. it changes from one form to the other but remains unaltered.
It is D as u dont need a stop watch aft that
It's about 6 minutes, as I seem to recall. Sort of the time for the earth to go into shadow darkness when there's an eclipse ???
Here refrigerator removes 55 kcal heat from freezer
Refrigerator releases 73.5 kcal heat to surrounding
So here we can use energy conservation principle by II Law of thermodynamics
the law says that

here we know that
= heat released to the surrounding
= heat absorbed from freezer
W = work done by the compressor
now using above equation we can write



So here compressor has to do 18.5 k cal work on it
Answer:
ENERGY AND COST. One kllowatt hour is 1,000 watts of power for one hour of time. ... Determine power: P = V XI ... Calculate the total kilowatt hours used. ... If the electric costs are 150 per kWh, how much does it cost to run the refrigerator in ... 8. A room was lighted with three 100-watt bulbs for 5 hours per day. If the cost of.
Explanation: