Question

If a π-meson at rest decays into a muon and a massless particle, and all the missing mass goes into the muon's kinetic energy, how fast will the muon move?

a)0.5c
b)0.6c
c)0.7c
d)0.8c

Answer 1

The muon will move at a speed close to the speed of light, which is 0.99c.

Step-by-step explanation:

To calculate the speed of the muon after the decay of the π-meson, we need to consider the conservation of momentum and energy.

The initial momentum of the π-meson is zero since it is at rest, and the final momentum is equal to the momentum of the muon.

Since the massless particle has no momentum, the total momentum before and after the decay is the same.

Therefore, the muon will have a speed close to the speed of light, which is 0.99c.