A stationary radium atom decays, emiting an alpha particle. Why is the recoil speed of the nucleus small compared to the alpha particle?
Initially the momentum is zero.
Due to conservation of momentum, the alpha particle and radium nucleus must gain equal but opposite momentum.
The mass of the radium nucleus is greater than the mass of the alpha particle.
Therefore, the alpha particle has a much greater speed after emission than the radium nucleus. (p = mv)
DD
Related Physics A Level answers
All answers ▸A model truck A of mass 1.2 kg is travelling due west with a speed of 0.90 m/s . A second truck B of mass 4.0 kg is travelling due east towards A with a speed of 0.35 m/s .
2 identical trolleys of mass M(one is loaded with 2 blocks of mass m) are on a ramp inclined at 35° and are connected by a wire that passes around a pulley at the top of the ramp. They are released and accelerate accordingly. Show that a=(mgsin35°)/(M+m).
What is the photoelectric effect?
"An inclined plane at an angle of 25 degrees to the horizontal has a pulley at its top. A 30kg block on the plane is connected to a freely hanging 20kg block by means of a cord passing over the pulley. From rest how far will the 20kg block fall in 2s?