Question

Two containers of ideal gas with identical initial conditions experience identical temperature increases. Container A goes through the increase isobarically (with constant pressure) and container B isochorically (with constant volume).

More heat was added to container A.

More heat was added to container B.

Equal amounts of heat were added to both containers.

Any of the above relations is possible, depending on the work. 12.5 points Question 3

Say that a person is playing an amplified stringed instrument while riding on a vehicle approaching you at considerable speed. In order for the person to perform so that the music sounds correct to you, the person should

have increased the tension in the strings.

finger the strings so as to make the portions of the strings that oscillate shorter.

do either of the above, since both will have the desired effect.

do something not listed above, since neither act will have the desired effect.

Answer 1

a) To raise the temperature of an ideal gas by a particular temperature difference, more heat energy has to be supplied to gas at constant pressure, than at constant volume. When heat is added to a gas at constant volume, the work done by the gas is zero. When heat is added at constant pressure, work is done by the gas while temperature is increased. So, the heat capacity of a gas at constant pressure is greater than the heat capacity at constant volume.

C_{​​​​​​p} > C_{​​​​​​v}

b) When the source of the sound is moving towards the observer, the frequency of the sound is increased according to the listener.

The frequency of vibration of a string increases as tge tension of string increases. The frequency of vibration increases when the length of string is decreased. To hear the sound correctly, the frequency of vibration of the string should be decreased. So, either the tension of the string has to be decreased, or the length of the string has to be increased.

So, do something not listed above, since neither act will have the desired effect.