Recent content by quirck

Once 15 years ago I was rushed to the hospital because I felt pain in my heart, and when they measured my blood the only thing they could find was that my cholesterol was unmeasurable they called it "below critical". I don't know if it was the cause of my feeling bad, but if it was, it feels awful.

A photon is emitted from a star in a far away galaxy. Its energy is hv = 1000 keV Its velocity is c. When it arrives at the retina, the redshift/doppler caused the photon to have an energy less than 1000keV. Where has the energy of the closed photon packet gone?

In this problem, energy is not conserved. Thank you for the quick reply. Very kind. I understand you want to stay simple here and this rule of thumb is applicable here, however I want to get a deep understanding of this. Most of all I want to try to get a grasp on what is momentum. Like...

Homework Statement 1 mass M1 of 1 kg moves frictionless at V1 1 meter per second to the right. It fuses with mass M2 of 2 kg and together they keep moving frictionless to the right. What is the speed V2 of the fused objects? Homework Equations Impulse mass * Velocity Kinetic energy...