A(n) absorbs energy and then emits electromagnetic radiation based on its . Classical physics predicted that at a high enough temperature, light would be emitted. Instead, white light was emitted, resulting in the ultraviolet . The photoelectric effect occurs when light shining on a metal creates a(n) . However, only light of a certain minimum causes electrons to flow. Gas atoms excited by an electric current emit bands of colors of light in a(n) . Each narrow band of light is associated with of a specific energy.

Which of the following statements does not explicitly describe a transfer of money a. a ball dropped from a heigh hits the ground with a high speed. b. the collision produced in a nuclear reaction heat up the surroundings. c. a plane increases its air speed from 150 mi/hr to 200 mi/hr. d. the electricity from the power socket causes the fan to turn.

Carbon is allowed to diffuse through a steel plate 15 mm thick. the concentrations of carbon at the two faces are 0.65 and 0.30 kg c/m^3 fe, which are maintained constant. if the preexponential and activation energy are 6.2 x 10-7 m2 /s and 80,000 j/mol, respectively, compute the temperature at which the diffusion flux is 1.43 x 10^-9 kg/m^2 -s.

I) a gas contained within a piston-cylinder assembly undergoes two processes, a and b, between the same end states, 1 and 2, where p1 = 10 bar, v1 = 0.1 m3 , u1 = 400 kj and p2 = 1 bar, v2 = 1.0 m3 , u2 = 200 kj: ' process a: process from 1 to 2 during which the pressure-volume relation is pv = constant. ' process b: constant-volume process from state 1 to a pressure of 2 bar, followed by a linear pressure-volume process to state 2. kinetic and potential energy effects can be ignored. for each of the processes a and b, a) sketch the process on a p-v diagram. b) evaluate the work, in kj. c) evaluate the heat transfer, in kj.(ans : qb,12 = -65.0 kj)