The question itself is relatively easy, but the numerical calculation may be a bit tedious. Let's see what we can do about it.
First, one should that the total energy can be written as
where
is the energy at rest (rest mass energy, in other words). [If you cannot remember this equation, just keep in mind that energy reaches infinity when
approaches
, and
appears everywhere in relativity. Then you can work the formula out.]
From the question, we can write equation for kaon's energy and proton rest energy as
We can arrange term and solve for
:
Now, the term we got is ugly. However, with Taylor's approximation and so on, we can find the answer
So, the answer should be (E).
The correct answer is (E). 37 of 100 got the correct answer.
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