A closed system contains 3 kg of R-134a, initially at 10 C and 90 kPa (State 1), and undergoes an internally reversible, isothermal process until the volume of the R-134a reaches 0.056 m3 (Stage 2). The system returns to State 1 by an irreversible process and the heat transfer for the return process is 3.2 kJ. Determine Q12, W12, W21, and

Awave travels at a speed of 5.2 m/s. if the distance between crests is 0.40 m, what is the frequency of the wave? use f=v/wavelength a. 13 hz b. 2.1 hz c. 0.077 hz d. 5.6 hz

Aperson stands on a platform, initially at rest, that can rotate freely without friction. the moment of inertia of the person plus the platform is ip. the person holds a spinning bicycle wheel with its axis horizontal. the wheel has moment of inertia iw and angular velocity ωw. take the ωw direction counterclockwise when viewed from above. part a what will be the angular velocity ωp of the platform if the person moves the axis of the wheel so that it points vertically upward?

Alfred pushes on a heavy box, but cannot move it. the box has a lot of inertia motion friction gravity