140 students sit in an auditorium listening to a physics lecture. because they are thinking hard, each is using 125 w of metabolic power, slightly more than they would use at rest. an air conditioner with a cop of 5.0 is being used to keep the room at a constant temperature. what minimum electric power must be used to operate the air conditioner?

An astronaut in space cannot use a scale or balance to weigh objects because there is no gravity. but she does have devices to measure distance and time accurately. she knows her own mass is 77.4 kg , but she is unsure of the mass of a large gas canister in the airless rocket. when this canister is approaching her at 3.50 m/s , she pushes against it, which slows it down to 1.30 m/s (but does not reverse it) and gives her a speed of 2.60 m/s . what is the mass of the canister?