Intro to Conservation of Momentum Practice Problems
An electron with a speed of 3.0 × 106 m/s collides with an atom (energy levels: n1 = -24.6 eV, n2 = -5.4 eV, n3 = -2.4 eV). The atom emits a 619.9 nm photon after the collision. Ignoring atomic recoil( as the atom's mass is significantly larger than the electron's), find the electron's final speed. Note: Photon energy ≠ collision energy.
During a football match, a player attempts to score a goal, but he misses and the ball with a speed of 55 m/s hits the goalpost and rebounds back with the same speed. The force exerted by the goalpost on the ball is depicted in the graph below. Determine the maximum force exerted by the goalpost on the ball if the mass of the football is 425 g. Consider the motion towards the right as positive.