A cement truck delivers mixed cement to a large construction site. Let x represent the cycle time in minutes for the truck to leave the construction site, go back to the cement plant, fill up, and return to the construction site with another load of cement. From past experience, it is known that the mean cycle time is $\mu=45$ minutes with $\sigma=12$ minutes. The x distribution is approximately normal. What is the probability that the cycle time will exceed 60 minutes, given that it has exceeded 50 minutes?

Consider the digraph with vertex-set V={A, B, C, D, E} and arc-set A={AB, AE, CB, CD, DB, DE, EB, EC}. (a) Find a path from vertex A to vertex D. (b) Explain why the path you found in (a) is the only posible path from vertex A to vertex D. (c) Find a cycle in the diagraph. (d) Explain why vertex A cannot be part of a cycle. (e) Explain why vertex B cannot be part of a cycle. (f) Find all the cycles in this diagraph.

Consider an ideal gas-turbine cycle with one stage of compression and two stages of expansion and regeneration. The pressure ratio across each turbine stage is the same. The high-pressure turbine exhaust gas enters the regenerator and then enters the low-pressure turbine for expansion to the compressor inlet pressure. Determine the thermal efficiency of this cycle as a function of the compressor pressure ratio and the high-pressure-turbine-to-compressor inlet temperature ratio. Compare your result with the efficiency of the standard regenerative cycle.

A Brayton cycle with regeneration using air as the working fluid has u pressure ratio of 7. The minimum and maximum temperatures in the cycle are 310 and 1150 K. Take an isentropic efficiency of 75 percent for the compressor and 82 percent for the turbine and an effectiveness of 65 percent for the regenerator. Determine the total exergy destruction associated with the cycle, assuming u source temperature of 1500 K and a sink temperature of 290 K. Also, determine the exergy of the exhaust gases at the exit of the regenerator. Use variable specific heats for air.

The carbon fusion cycle is one way that a star is fuelled. Through a series of processes, carbon atoms combine with hydrogen to form other elements such as nitrogen and oxygen, before returning back to carbon. Throughout this cycle, energy is released. In one step ofthe carbon fusion cycle, nitrogen-13 spontaneously decays into carbon-13. Suppose that in a laboratory simulation, a sample of nitrogen-13 is measured to be 10% of its initial amount after approximately 33 min. Determine the half-life of nitrogen-13.

Consider a Carnot-cycle heat engine with water as the working fluid. The heat transfer to the water occurs at $300^{\circ} \mathrm{C}$, during which process the water changes from saturated liquid to saturated vapor. The heat is rejected from the water at $40^{\circ} \mathrm{C}$. Show the cycle on a T-s diagram and find the quality of the water at the beginning and the end of the heat rejection process. Determine the net work output per kg water and the cycle thermal efficiency.

Air in a piston/cylinder goes through a Carnot cycle in which TL = 560 R and the total cycle efficiency is $\eta$ =2/3. Find TH, the specific work, and the volume ratio in the adiabatic expansion for constant Cp, Cv.

Consider a steam power plant operating on the ideal Rankine cycle with reheat between the pressure limits of 30 MPa and 10 kPa with a maximum cycle temperature of $700^{\circ} \mathrm{C}$ and a moisture content of 5 percent at the turbine exit. For a reheat temperature of $700^{\circ} \mathrm{C},$ determine the reheat pressures of the cycle for the cases of (a) single and (b) double reheat.

Graph one complete cycle of

$$y = 2 \cos ( 2 x + \pi )$$

What would happen to the rock cycle if erosion did not occur?

A cement truck delivers mixed cement to a large construction site. Let x represent the cycle time in minutes for the truck to leave the construction site, go back to the cement plant, fill up, and return to the construction site with another load of cement. From past experience, it is known that the mean cycle time is $\mu=45$ minutes with $\sigma=12$ minutes. The x distribution is approximately normal. What is the probability that the cycle time will exceed 55 minutes, given that it has exceeded 40 minutes?

The cycle time for trucks hauling concrete to a highway construction site is uniformly distributed over the interval 50 to 70 minutes. What is the probability that the cycle time exceeds 65 minutes if it is known that the cycle time exceeds 55 minutes?

Assume we change the Otto cycle in Problem 10.152E to an Atkinson cycle by keeping the same conditions and only increase the expansion to give a different state 4. Find the expansion ratio and the cycle efficiency.Problem 10.152Air flows into a gasoline engine at 14 lbf/in.2, 540 R. The air is then compressed with a volumetric compression ratio of 10:1. In the combustion process, 560 Btu/lbm of energy is released as the fuel burns. Find the temperature and pressure after combustion.

"The Storyteller" and "Harmless Fun?" both address the topic of -

A. entertaining children with whatever is available B. letting children behave inappropriately C. guiding children toward good behavior D. watching children carefully all the time