Answer:
If one end of a metal bar is heated, the atoms at that end vibrate more than the atoms at the cold end. The vibration spreads along the bar from atom to atom.
Explanation:
The spread of heat in this way is called conduction. Metals are good conductors of heat.
Answer:
It will emerge at its initial speed not a slower speed.
Explanation:
It will emerge at the initial speed because the medium at the point of emergence is the same as the medium before incidence.
Light moves at a constant speed in any particular medium. Hence, the speed of light in air is constant in air and the speed of light in glass is constant in glass.
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
Light energy is not kinetic energy