When a valve on a pipe is suddenly closed, a wave is created that results in the phenomenon known as water hammer. The pressure associated with a wave of this type can be substantial and may cause damage to the pipe. The maximum pressure developed, pmax, is known to be a function of the fluid density rho, the bulk modulus Ev , and the initial flow velocity V. Determine the number of Pi groups that can be formed from these four parameters. Use the repeating variable method to determine the functional form of each of the Pi groups associated with the water hammer wave described in above problem. Verify that each Pi group is dimensionless. Identify the names of each dimensionless Pi group, if any, and rewrite the relationship among Pi groups using the appropriate symbols for each standard group.

Under conditions for which the same room temperature is maintained by a heating or cooling system, it is not uncommon for a person to feel chilled in the winter but comfortable in the summer. provide a plausible explanation for this situation (with supporting calculations) by considering a room whose air temperature is maintained at 20â°c throughout the year, while the walls of the room are nominally at 27â°c and 14â°c in the summer and winter, respectively. the exposed surface of a person in the room may be assumed to be at a temperature of 32â°c throughout the year and to have an emissivity of 0.90. the coefficient associated with heat transfer by natural convection between the person and the room air is approximately 2 w/m2 â‹…â‹… k. what is the ratio of the thermal resistance due to convection to the thermal resistance due to radiation in the summer? what is the ratio of thermal resistances in the winter

If 21.2 kcals of energy is released by this reaction, how many kj does the reaction release? (1 cal 4.184 j)

Using a pedometer, you walk 3000 steps in 20 minutes, so your speed is 150 steps/min. each of your steps is 0.7 m long. what is your speed? 150 steps/min=/s=/h