1. What do you meant by vibrations? 2. What is the other name for larynx?
3. Do all animals produce sound by vocal chords?
4. Write the unit of frequency.
5. What do you mean by noise pollution?
6. What is the loudness of a normal conversation?
7. Explain importance of sound in our daily life.
8. Name the organ in human that produces sound. How does it work?
9. Prove that sound travels in solids too.
10. How does loudness of sound is affected by amplitude?

Acommercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at -35°c by rejecting waste heat to cooling water that enters the condenser at 18°c at a rate of 0.25 kg/s and leaves at 26°c. the refrigerant enters the condenser at 1.2 mpa and 50°c. if the compressor consumes 3.3 kw of power, determine (a) the mass flow rate of the refrigerant, (b) the refrigeration load, (c) the cop, and (d) the minimum power input to the compressor for the same refrigeration load.