Answer:
1. how fast things move - mechanics
2. how the shape of a cave affects an echo - Sound & acoustics
3. which sunglasses are best for cutting the glare on a ski slope - optics
4. how the cooling system in a refrigerator works - thermodynamics
5. what lightning is - Electricity
6. how energy is produced by the sun – nuclear physics
Explanation:
Mechanics - the study of the motions of the objects
Sound - the study of the behavior of sound waves
Optics - the study of the behavior of light waves and optical instruments
Thermodynamics - the study of the relationship between heat and other forms of energy
Electricity - the study of properties of charges, their movement and their field interactions
Nuclear physics - study of atomic nucleus and its properties
