Suppose that an electron and a positron collide head-on. Both have kinetic energy of 1.20 MeV and rest energy of 0.511 MeV. They produce two photons, which by conservation of momentum must have equal energy and move in opposite directions. What is the energy Ephoton of one of these photons

1. how to locate the image in converging(concave) mirror and diverging (convex) mirror with salt. 2. how to locate the image in a converging (convex) lens and diverging (concave) lens with salt.

Abox is sliding on a frictionless surface when it suddenly begins to rain heavily. if the downpour of rainfall falls vertically into the box

A0.5-kg object is connected to a spring that undergoes oscillatory motion. there is friction between the object and the surface it is kept on given by coefficient of friction μk = 0.06 . if the object is released 0.2 m from equilibrium, what is the distance that the object travels? given that the force constant of the spring is 50 n m-1 and the frictional force between the objects is 0.294 n.