An argon ion laser puts out 5.0 w of continuous power at a wavelength of 532 nm. the diameter of the laser beam is 5.5 mm. if the laser is pointed toward a pinhole with a diameter of 1.2 mm, how many photons travel through the pinhole per second? assume that the light intensity is equally distributed throughout the entire cross-sectional area of the beam. (1 w = 1 j/s)

Number of photons travel through pin hole=

Explanation:

First we will calculate the energy of single photon using below formula:

Where :

h is plank's constant with value

c is the speed of light whch is

λ is the wave length = 532nm

E=J

Number of photons emitted per second:

Number of photons emitted per second=

=

Where:

A-hole is area of hole

A-beam is area of beam

d-hole is diameter of hole

d-beam is diameter if beam

=

=

=

Number of photons travel through pin hole=

Number of photons travel through pin hole=

the answer is b ) square root of 5

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.