Answer:
2.33*10^-15 s
Step-by-step explanation:
We need to estimate the period of oscillation of an electron that bounced up/down due to the effects of a passing packet of red light. The period of oscillation is the wavelength of the red light divided by the speed of the red light. We know that:
V = f*λ
where V = speed of the red light = 3*10^8 m/s
f = frequency = 1/T where T is the period of oscillation in seconds (s)
λ = the wavelength of the red light = 0.7*10^-6 m
Thus:
V = λ/T
T = λ/V = (0.7*10^-6)/(3*10^8) = 2.33*10^-15 s