Midterm
a linear circuit is shown below.

the elements in this circuit have the following values: r1=200ω, r2=200ω, r3=100ω, v1=5v, i1=0.001a and i2=0.005a
determine the potentials at nodes a and b, assuming a ground node as shown in the figure.

(a) what is the value of voltage va in volts?
(b) what is the value of voltage vb in volts?
now let us determine if the answers you came up with satisfy the laws of physics.

what is the power (in watts) dissipated in resistor r1?
what is the power (in watts) dissipated in resistor r2?

Comedians like to joke that the reason we haven’t been visited by intelligent life from elsewhere in the universe is that aliens have been monitoring earth’s broadcasts of intellectually embarrassing tv programs, like gilligan’s island, fear factor, the jersey shore, and the jerry springer showand so consider us far too primitive to merit a visit. let’s check the assertion that aliens could have been receiving them. tv programs are broadcast at a frequency of about 100mhz with about 100kw of total power in 30frames per second, which emanatesroughly uniformly in all directions. assume that interstellar space transmits these broadcasts without attenuation. no matter how smart they are, aliens would require at least one photon per frame to interpret our signals. findthe number of photons per unit time per unit area reaching a receiver on a possible planet in the nearest star system, which is about 4 light-years away (a light-year is the distance light travels in a year). if aliens aimed a receiver or detector directly at earth, how big (in diameter) would it have to be to receive a photon per frame

The experiment was repeated many years later but the gases were mixed in a different type of container. a white solid was obtained which was xenon fluoride. predict whether you think 1) krypton and 2) radon will react with fluorine. explain reasons for your predictions

In what direction does an applied force move an object