A radioactive nucleus at rest decays into a second nucleus, an electron, and a neutrino. The electron and neutrino are emitted at right angles and have momenta of 9.15×10−23 kg . m/s and 5.19×10−23 kg . m/s, respectively.

Question

A radioactive nucleus at rest decays into a second nucleus, an electron, and a neutrino. The electron and neutrino are emitted at right angles and have momenta of 9.15×10−23 kg . m/s and 5.19×10−23 kg . m/s, respectively.
1.)What is the magnitude of the momentum of the second (recoiling) nucleus? 
2.)What are the direction of the momentum of the second (recoiling) nucleus? (theta  =    from the momentum of the electron)

drwls · Answer

Draw yourself a triangle with the neutrino and electron forming two sides at right angle. The hypotenuse will be the momentum of the nucleus, so that the sum of momenta remains zero.

Solve the triangle using simple rules of trigonometry.

The angle theta is, I believe,
180 - arctan 5.19/9.15
= 150.4 degrees

mohammed · Answer

caculate the k.e of car with mass of 50kg and velocity of 10m/s