Air containing 0.06% carbon dioxide is pumped into a room whose volume is 12,000 ft^3. the air is pumped in at a rate of 3,000 ft^3/min, and the circulated air is then pumped out at the same rate. if there is an initial concentration of 0.3% carbon dioxide, determine the subsequent amount a(t), in ft3, in the room at time t.

Ais useful when you need a simple machine to you separate two things. a. lever b. screw c. pulley d. wedge

Classify each possible hypothesis about a medicinal aloe vera plant as falsifiable or non-falsifiable. aloe vera gel is the best natural skin moisturizer. aloe vera gel can heal wounds by boosting cell renewal. aloe vera juice tastes better than carrot juice. drinking aloe juice can reduce the risk of lung cancer.

The electric field between square plates of a parallel-plate capacitor has magnitude e. the potential across the plates is maintained with constant voltage by a battery as they are pulled apart to twice their original separation, which is small compared to the dimensions of the plates. the magnitude of the electric field between the plates is now equal to a)e b)e/4 c)e/2 d)4e e)2e