Consider three straight infinitely long (parallel to each other), equally spaced wires (with distance d), each carrying a current i in the same direction.
assume the three wires are coplanar. (eg. they are lying on the x, y plane where z = 0) , if the middle wire is rigidly displaced a very small distance x (x < < d) upward(in the z direction) while the other two wires are held fixed. analyze and describe the resulting motion of the middle wire. be specific in terms of magnetic field and gravity.

Glass is transparent to visibile light under normal conditions; however, at extremely high intensities, glass will absorb most of the light incident upon it. this works through a process known as multiphoton absorption. in this process, several photons are absorbed at the same time. if very intense light whose photons carry 2ev of energy is shined onto a material with a band gap of 4ev, that light can be absorbed through two-photon absorption, because two photons have the right amount of energy to bridge the band gap. what is the minimum number of photons of 800-nm light that are needed to equal or exceed the band gap of fused silica glass

Which situation will produce the greatest change of momentum

An architect plans to use solar energy to heat the next house he designs. what principle of absorption and infrared energy can be applied to the design of the new house? how could she apply to those principals?