Based on the position vs. time graph, which velocity vs. time graph would correspond to the data? a graph with horizontal axis time (seconds) and vertical axis position (meters). a line runs straight upward from 0 seconds 0 minutes. a graph labeled velocity versus time with horizontal axis time (seconds) and vertical axis velocity (meters per second). a line runs in straight segments from 0 seconds 0 meters per second to 1 second 15 meters per second to 2 seconds 20 meters per second to 4 seconds 20 meters per second to 5 seconds 0 meters per second. a graph labeled velocity versus time with horizontal axis time (seconds) and vertical axis velocity (meters per second). a straight line begins at 0 seconds 0 meters per second and runs to 5 seconds 5 meters per second. a graph horizontal axis time (seconds) and vertical axis velocity (meters per second). a straight line begins at 0 seconds 2 meters per second and runs to 5 seconds 2 meters per second. a graph labeled velocity versus time with horizontal axis time (seconds) and vertical axis velocity (meters per second). a straight line begins at 0 seconds 10 meters per second and runs to 5 seconds 2 meters per second.

In a wind tunnel the speed changes as the cross sectional area of the tunnel changes. if the speed in a 6' x 6' square test section is 100 mph, what was the speed upstream of the test section where the tunnel measured 20' x 20'? use conservation of mass and assume incompressible flow. conservation of mass requires that as the flow moves through a path or a duct the product of the density, velocity and cross sectional area must remain constant; i.e., that ova-constant. a model is being tested in a wind tunnel at a speed of 100 mph if the flow in the test section is at sea level standard conditions, what is the pressure at the model's stagnation point? (a) the tunnel speed is being measured by a pitot-static tube connected to a u- tube manometer. what is the reading on that manometer in inches of water? (b) at one point on the model a pressure of 2058 psf is measured. what is the local airspeed at that point?

Select the correct answer from each drop-down menu. compared to its surroundings, the concentration of solutes is low inside a cell. so, the cell is with respect to its surroundings. a particular solute in this cell uses energy for its transport from the cell to its surroundings. this type of transport is called

An internally reversible refrigerator has a modified coefficient of performance accounting for realistic heat transfer processes of where qin is the refrigerator cooling rate, qout is the heat rejection rate, and is the power input. show that copm can be expressed in terms of the reservoir temperatures tc and th, the cold and hot thermal resistances rt,c and rt,h, and qin, as where rtot rt,c rt,h. also, show that the power input may be expressed as 1.39 a household refrigerator operates with cold- and hot-temperature reservoirs of tc 5 c and th 25 c, respectively. when new, the cold and hot side resistances are rc,n 0.05 k/w and rh,n 0.04 k/w, respectively. over time, dust accumulates on the refrigerator’s condenser coil, which is located behind the refrigerator, increasing the hot side resistance to rh,d 0.1 k/w. it is desired to have a refrigerator cooling rate of qin 750 w. using the results of problem 1.38, determine the modified coefficient of performance and the required power input w under (a) clean and (b) dusty coil conditions. internally reversible refrigerator qout qin w high-temperature reservoir low-temperature reservoir th th,i tc,i tc high-temperature side resistance low-temperature side resistance w qin th tc qinrtot tc qinrtot copm tc qinrtot th tc