Green light (520 nm) enters glass with n = 1.52. What is the wavelength of light in glass?
(Unit=nm)

Letter a, because when there are unlike charges they will always attract to each other.

B) erini just took the test and it is correct

The answer is 4f======since electrostatic force is given by    we let f be the electrostatic force when  r = 1 m    if we let  denote the electrostatic force when the distance is decreased so that r = 0.5m, then    we established earlier that f = kq₁q₂. therefore    the force will now be 4f.