Why do people amswer my dumb questions but not my homework questions

To create electromagnetic induction, which of the following has to move? a. a wire b. a magnet c. a transformer d. either a or b

Consider an ordinary, helium-filled party balloon with a volume of 2.2 ft3. the lifting force on the balloon due to the outside air is the net resultant of the pressure distribution exerted on the exterior surface of the balloon. using this fact, we can derive archimedes’ principle, namely that the upward force on the balloon is equal to the weight of the air displaced by the balloon. assuming that the balloon is at sea level, where the air density is 0.002377 slug/ft3, calculate the maximum weight that can be lifted by the balloon. note: the molecular weight of air is 28.8 and that of helium is 4.

Aregion of space in which a measurable gravitational force is indicated by the force exerted on a test mass is called