Aperson listening to a siren from a stationary police car observes the frequency and wavelength of that sound. the car now drives rapidly away from the person.
o the wavelength of the sound the person observes will be shorter than it was, but the frequency will not be changed.
o the frequency of the sound the person observes will be higher than it was, but the wavelength will not be changed.
o the wavelength of the sound the person observes will be longer than it was, and the frequency will also be lower than it was.
o the wavelength of the sound the person observes will be shorter than it was, and the frequency will also be higher than it was.

I) a gas contained within a piston-cylinder assembly undergoes two processes, a and b, between the same end states, 1 and 2, where p1 = 10 bar, v1 = 0.1 m3 , u1 = 400 kj and p2 = 1 bar, v2 = 1.0 m3 , u2 = 200 kj: ' process a: process from 1 to 2 during which the pressure-volume relation is pv = constant. ' process b: constant-volume process from state 1 to a pressure of 2 bar, followed by a linear pressure-volume process to state 2. kinetic and potential energy effects can be ignored. for each of the processes a and b, a) sketch the process on a p-v diagram. b) evaluate the work, in kj. c) evaluate the heat transfer, in kj.(ans : qb,12 = -65.0 kj)