Optical tweezers use light from a laser to move single atoms and molecules aroun

Question

Optical tweezers use light from a laser to move single atoms and molecules around. Suppose the intensity of light from the tweezers is 1000 W/m2, the same as the intensity of sunlight at the surface of the Earth.

(a) What is the pressure on an atom if light from the tweezers is totally absorbed? ANS: 3.33e-6 Pa

(b) If this pressure were exerted on a tritium atom, what would be its acceleration? (The mass of a tritium atom is 5.01 1027 kg. Assume the cross-sectional area of the laser beam is 6.65 1029 m2.) m/s2

Explanation / Answer

a) P abs = intensity/c
P abs = 1000/3*10^8 = 333.33*10^-8 Pa
b) F = Pabs * A = 2.2166*10^-34 m/s/s = ma = 3.016*1.66*10^-27*a
a = 4.4275*10^-8 m/s/s

Related Questions

Navigate

• Browse (All)
• Browse O
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.