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? ? 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 ✕ 10−27 kg. assume the cross-sectional area of the laser beam is 6.65 ✕ 10−29 m2.)

(a)  

The radiation pressure exerted by an electromagnetic wave on a surface that totally absorbs the radiation is given by

where

I is the intensity of the wave

c is the speed of light

In this problem,

and substituting , we find the radiation pressure

(b)

Since we know the cross-sectional area of the laser beam:

starting from the radiation pressure found at point (a), we can calculate the force exerted on a tritium atom:

And then, since we know the mass of the atom

we can find the acceleration, by using Newton's second law:

if the person is shown to have +90n, then ans is -10n.

if the person is shown to have -90n, then ans is +10n.

pythagoras' theorem

square root (-5^2+9^2)

square root (25+81)

square root (106)

angle is tan^-1(9/5)

neg x, pos y