What causes a bolt of lightning?

a. electrical charges build up in the clouds only.

b. electrical charges build up on the ground only.

c. electrical charges build up in the clouds and on the ground.

d. electrical charges build up in the space between the clouds and the ground.

Which pair of quantities includes one quantity that increases as the other decreases during simple harmonic motion?

Consider the growth of a 20-nm-diameter silicon nanowire onto a silicon wafer. the temperature of the wafer surface is maintained at 2400 k. assume the thermal conductivity of the silicon nanowire is 20 wm-1k-1 and all its surfaces including the tip are subjected to convection heat transfer with the coefficient h = 1×105 wm-2k-1 and t∞ = 8000 k. when the nanowire grows to l = 300 nm, what is the temperature of the nanowire tip (t (x =

Which describes increasing the efficiency of energy resource