6. An educational researcher is interested in the relationship between students? participation in two after school programs and academic achievement. She states
the following hypothesis in the description of her study:
H.1. Children who participate in an after school program that emphasizes critical
thinking skills will score higher on measures of academic achievement and self-esteem
than students who participate in a program that emphasizes rote memorization,
What are the variables in this study?​

To save energy, the air supply to a 2000 ft office has been shut off overnight and the room temperature has dropped to 40°f. in the morning, the thermostat is reset to 70°f and warm air at 120 f begins to flov in at 200ft'/min. the air is well mixed within the room, and an equal mass flow of air at room temperature (changing with time) is withdrawn through a return duct. the air pressure is nearly 1 atm everywhere. ignoring heat transfer with the surroundings and kinetic and potential energy effects, estimate how long it takes for the room temperature to reach 70°f. plot the room temperature as a function of time.