When you play a piano, your energy increases in a uniform, continuous manner and is therefore quantized.When you play a piano, you can press only on individual keys, so that your energy is restricted to certain values and is therefore quantized.
Arrows point away from both north and south.
Answer:

Explanation:
= Permittivity of free space = 
= Surface charge density = 
= 0.57-0.26
q = Charge = 
m = Mass of object = 
Electric field due to a sheet is given by

Electric field is given by

Voltage is given by

Kinetic energy is given by


The initial speed of the object is 
Answer:
Buttery popcorn contained in a large 1 liter bowl has a mass of about 50 mg and about 650 calories.
Explanation:
Liter is the most appropriate unit to measure a bowl. Usually 1 liter of liquid has a mass of 1000 gram. Since popcorn is something lightweight and only a few can fill the bowl quickly so 50 mg makes perfect sense with 1 liter of bowl and 650 calories in buttery popcorn.