The proton (mass M) and electron (mass m) in a hydrogenatom actually rotate about their commoncenter of mass as shown in Figure 4.17. The distancer re rM is still defi ned to be the electron-nucleusdistance. Show that Equation (4.24) is only modifi edby substituting for m bym m1 m/M

Chapter 10 Notes- Momentum The momentum of an object is the product of its mass and velocity. Momentum moves in the same direction as a particles velocity. The dimension for momentum is a kg*m/s. The formula for momentum is: p=mv The center of mass is shown by the formula: x =( m2 )x CM m1+m 2 2 For center of mass multiply the associated mass with the associated x coordinate. With momentum the initial momentum is going to be the same as the final momentum, and we know that for every action the is an equal and opposite reaction so for problems that ask for the recoil momentum, we use the following: m v =m v