Hi, I have a few questions from waves, thermodyanamics and capacitors. Please help me with them. Two vibrating tuning forks produce progressive waves given by y1 = 4 sin(500pt) ........ p = pi = 3.14159 and t is time y2 = 2 sin(506pt). Then how many beats are heard per minute? -- How do I deal with it? If I try to add them trigonometrically, I am unable to express it as a product of two trigonometrical functions, which is necessary. In a stationary wave pattern that is formed as a result of reflection from an obstacle, the ratio of the amplitude at an antinode and a node is b = 1.5. What percentage of energy passes through the obstacle? -- Any hint please because I have no idea how to begin with this question. Some gas at 300K is enclosed in a container. Now it is placed in a fast moving train. Then what will happen to the temperature of the gas? The initial pressure (P) and Volume(V) are same. Two processes one isothermal and other isobaric are carried out both ending at the same volume. In which case is more energy given to the gas as heat? -- I know Q(isothermal) = nRT ln(Vf/Vi) Vf = final volume, Vi = initial volume Q(isobaric) = n Cp (T2-T1) Cp= Molar specific heat at constant P. How do I compare these expressions? Why does sprinkling of water reduces temperature of a closed room? -- I think this is so because water absorbs the heat to get to the same temperature as that of the room. Am I right? What will happen if a substance has infinite specific heat? Which is better to extinguish a fire - hot water, cold water, ice? -- I am confused with this as the answer is given hot water. Ice must be the answer, according to me, because it can absorb maximum heat before evaporating. And last but not the least, The capacity of a capacitor is 1F. It's resistance in a DC circuit will be infinite or zero? -- If in a circuit there is a capacitor we initially replace it with a wire and after a long time we replace it with a broken wire. So the answer must be both. Am I right?