Anarrow copper wire of length l and radius b is attached to a wide copper wire of length l and radius 2b, forming one long wire of length 2l. this long wire is attached to a battery, and a current is flowing through it. if the electric field in the narrow wire is e, the electric field in the wide wire is

(a) e
(b) 2e
(c) 4e
(d) e/2
(e) e/4

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.

An object of dimensions 50 cm x 40 cm x 0.20 cm has a mass 60g. find its density in g/cm3 and kg/ m3

Ryan is examining the energy of the particles in a bar of gold. what is ryan most likely studying?