Why is a specimen smaller than 200 nm not visible with a light microscope?

In what direction does the medium move relative to the direction of the wave? explain.

Matter is needed to transfer thermal energy bya. conductionb. convectionc. radiation d. both a & b.

Consider a system with two masses that are moving away from each other. why will the kinetic energy differ if the frame of reference is a stationary observer or one of the masses?