Answer:
Sound waves travel at 343 m/s through the air and faster through liquids and solids. The waves transfer energy from the source of the sound, e.g. a drum, to its surroundings. Your ear detects sound waves when vibrating air particles cause your ear drum to vibrate. The bigger the vibrations the louder the sound.
Explanation:
The correct answer for the first one is A) Breaking rocks into smaller pieces. The correct answer to the second one is A) It has more energy. Hope this helps.
Explanation:
It is given that,
The volume of a right circular cylindrical, 
We know that the volume of the cylinder is given by :

............(1)
The upper area is given by :



For maximum area, differentiate above equation wrt r such that, we get :



r = 1.83 m
Dividing equation (1) with r such that,



Hence, this is the required solution.