Show that an irreversible isothermal expansion of an ideal gas against constant external pressure (P2), from an initial state of P1, V1, T to P2, V2, T, with P2 less than P1, is a spontaneous process by showing that ASuniv is positive. You will need to calculate ASsus and AS surr - upload your calculations for each separately below. You may show that ASuniv is positive graphically. (By calculate, I mean to show that the signs and relative magnitudes of AS sys and AS surr are appropriate. A sketch of the graph is ok.)

One cycle of the signal on the oscilloscope screen has width of 2.8 cm (1 division = 1 cm). The setting on the Horizontal TIME/DIV control is 2 us. The period of the signal is us. Write your answer in the tenths place. Only the numerical value will be graded. One cycle of the signal on the oscilloscope screen has width of 2.8 cm (1 division = 1 cm). The setting on the Horizontal TIME/DIV control is 2 us. The frequency is kHz. Write your answer in the tenths place. Only the numerical value will be graded.

In the pair production process, photon energy gets converted to particle/antiparticle pairs. Imagine a single photon in free space, turning into one electron and one positron (antielectron), each with mass mec?. Assume for simplicity both particles move together with equal momenta in the same direction as the original photon as shown, and the photon disappears. Prove this can't happen!