chemical, potential energy is stored in a battery.
the negative end of a battery is connected to a wire.
the wire loops numerous times around a piece of steel.
the wire returns to the positive end of the battery.

what happens to the piece of steel?
a) it begins to spin.
b) it gains a negative charge.
c) it gains a positive charge.
d) it moves toward a piece of iron.

Light traveling in water, nwater = 1.33, strikes a plastic block at an angle of incidence of 51.4°; part of the beam is reflected and part is refracted. if the index of refraction of the plastic is 2.0, what is the angle made by the reflected and refracted beams?

Asteel tube (k=50 w/mk) of inner and outer diameter di = 20mm and do=26mm, respectively, is used to transfer heat from hot gases flowing over the tube (h-hot = 200w/m2k) to cold water flowing through the tube (h-cold = 8000 w/m2k). what is the cold-side overall heat transfer coefficient uc? to enhance heat transfer 16 straight fins of rectangular profile are installed longitudinally along the outer surface of the tube. the fins are equally spaced around the circumference of the tube, each having a thickness of 2mm and a length of 15mm. what is the corresponding overall heat transfer coefficient uc? *solve for uc in both cases*

Is a volume of space that is empty of matter.