Achild holds up a silver spoon and is surprised to see her reflection there.
which interaction between light and matter explains this?
a.
when light hits something relatively flat, smooth, and shiny, it is transmitted by the surface, allowing nearby objects to be seen on the surface.
b.
when light hits something relatively flat, smooth, and shiny, it is refracted by the surface, allowing nearby objects to be seen on the surface.
c.
when light hits something relatively flat, smooth, and shiny, it bounces off the surface, allowing reflected objects to be seen on the surface.
d.
when light hits something relatively flat, smooth, and shiny, it is absorbed by the surface, allowing refracted objects to be seen on the surface.

Tungsten-filament lightbulb emits light based on the temperature of the filament. which phenomenon does this demonstrate?

Three different objects, all with different masses, are initially at rest at the bottom of a set of steps. each step is of uniform height . the mass of each object is a multiple of the base mass : object 1 has mass 4..00m , object 2 has mass 1..96m , and object 3 has mass . when the objects are at the bottom of the steps, define the total gravitational potential energy of the three-object system to be zero. if the objects are then relocated as shown, what is the new total potential energy of the system? each answer requires the numerical coefficient to an algebraic expression. each algebraic expression is given using some combination of the variables , , and , where is the acceleration due to gravity. enter only the numerical coefficient. (example: if the answer is 1..23mgd , just enter 1.23)

Air enters a gas turbine with two stages of compression and two stages of expansion at 100 kpa and 17°c. this system uses a regenerator as well as reheating and intercooling – the intercooler returns the air to the inlet temperature. the pressure ratio across each compressor is 4 ; 300 kj/kg of heat are added to the air in each combustion chamber; and the regenerator operates perfectly while increasing the temperature of the cold air by 20°c. determine the system’s thermal efficiency. assume isentropic operations for all compressor and the turbine stages and use constant specific heats at room temperature. (0.378)