Two small nonconducting spheres have a total charge of Q = Q1 +Q2 = 91.0 pC, Q1 < Q2. When placed 32.0 cm apart, the force each exerts on the other is 12.0 N and is repulsive. a) what is the charge of Q1
b) what is the charge of Q2
c) what would Q1 be if forces attract
d) what would Q2 be if forces attract​

A150 w lamp emits light of wavelength 590 nm uniformly in all directions. what is the photon flux (photons per unit area per unit time) on a small screen at a distance 2.3 m from the lamp? assume the photons are uniformly distributed over the surface of a sphere of radius 2.3 m.

2.22/3.33 points | previous answers tamucolphysmechl1 4.pre.002. ask your teacher my notes question part points submissions used on a frictionless air track, a blue glider with mass 0.200 kg is moving to the right with a speed of 8.00 m/s. it strikes a red glider that has mass 0.600 kg and that is initially at rest. after the collision, the blue glider is moving to the left with a speed of 2.40 m/s. (a) what are the magnitude and direction of the velocity of the red glider after the collision? magnitude 3.33 m/s correct: your answer is correct. direction correct: your answer is correct. (b) is this collision elastic?

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