Two circular rods, both of length l and having the same diameter, are placed end to end between rigid supports with no initial stress in the rods. the coefficient of linear expansion and young's modulus for rod a are αa and ya respectively; those for rod b are αb and yb respectively. both rods are "normal" materials with α> 0. the temperature of the rods is now raised by δt.

what is the stress f/a in the rods after heating? express the stress in terms of ? a, ? b, ya, yb, and ? t.

1. what is the relationship between wavelength and the penetrating power of an electromagnetic wave? a) the penetrating power has no relationship to the wavelength. b) the penetrating power increases as the wavelength increases. c) the penetrating power decreases as the wavelength increases. d) the penetrating power decreases as the wavelength decreases. 2. as ice melts and turns into water, the speed of sound through the material would most likely do what? justify your answer. a) the speed would not change because the material is always water. b) the speed of sound would increase because the density of water is less than that of ice. c) the speed of sound would increase because energy is added to ice in order to make it melt. d) the speed of sound would decrease because sound travels faster through solids than liquids. 3.which of these waves need a medium to travel through? a) sound b) x-rays c) infrared rays d) visible light