Worked Example 01

The Question

Imagine that you are doing particle physics experiments. You fire a beam of sub-atomic particles of mass 4.0x10^-24 kg into your detector at a speed of 100 m/s. Most pass straight through undeflected, but one of them came out with its mass reduced to 3.0x10^-24 kg, its speed reduced to 80 m/s, and in a direction which was deflected by 2.4 degrees from its original path. You think that it must have ejected a particle of mass 1.0x10^-24 kg. To help you find the trace that this particle made in your detector, you need to calculate in what direction it would have been moving. What angle to the original direction of motion would it have ben traveling in, and at what speed?

The Answer

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