HEL PL A group of students is investigating whether air resistance depends on the size of an object. The students throw two paper pieces each with the same force. One piece of paper is flat and the other is scrunched into a ball. The distance traveled by each paper piece is shown. Experimental Observations Student 1 Student 2 Student 3 Student 4 Distance traveled by flat paper 0.2 m 1.2 m 1.5 m 0.8 m Distance traveled by scrunched paper 1.5 m 2.4 m 3 m 2 m What was the test variable (independent variable) in this experiment? A. Distance traveled by flat paper B. The shape of the paper C. Distance traveled by scrunched paper D. The number of students

Steam is generated in a boiler of a cogeneration plant at 10 mpa and 450°c at a steady rate of 5 kg/s. in normal operation, steam expands in a turbine to a pressure of 0.5 mpa and is then routed to the process heater, where it supplies the process heat. steam leaves the process heater as a saturated liquid and is pumped to the boiler pressure. in this mode, no steam passes through a condenser, which operates at 20 kpa. (a) determine the power produced in the turbine and the rate at which process heat is supplied in this mode. (b) determine the power produced in the turbine and the rate of process heat supplied if only 60 percent of the steam is routed to the process heater and the remainder is expanded to the condenser pressure. (3.32 mw; 9.69 mw; 4.25 mw; 5.82 mw)

The speed of sound in ice, water, and steam is shown. what best explains the speed of sound in different states of matter? sound travels fastest in ice because energy is easier to transfer when the molecules are close together. sound travels slowest in steam because the sound has to move around the gas molecules that are far apart. sound travels fastest in ice because the temperature of solids is always greater, so the heat transfers the sound energy. sound travels slowest in steam because the pressure is so great the sound cannot travel though the steam particles.

If an athlete runs once around a track, back to the starting line, her average velocity is zero. true or false?