Question

A rifle bullet (mass = 1.50 g) is moving with a velocity of 850. mph. What is the wavelength associated with this bullet?

Assume your eyes receive a signal consisting of blue light, = 470 nm. The energy of the signal is 2.5 10-14 J. How many photons reach your eyes?



You must convert 850 mph to m/s, then use lambda = h/mv. h is Planck's constant and lambda will be in meters.

For part b, E = hc/lambda.
You know h, you know c (in meters/second) and lambda (must be convert from nm to m). Calculate E for ONE 470 nm photon, then calculate the number of photons in the 2.5 x 10^-14 J.


Ignore the previous post and go to the next. My hand slipped and I posted before I intended to post.


You must convert 850 mph to m/s, then use lambda = h/mv. h is Planck's constant and lambda will be in meters.

For part b, E = hc/lambda.
You know h, you know c (in meters/second) and lambda (must be converted from nm to m). Calculate E for ONE 470 nm photon, then calculate the number of photons in the 2.5 x 10^-14 J. Post your work if you get stuck. We can help better that way.