Apion lives 26 ns in its rest frame. it travels 15 cm down a beam pipe in a particle accelerator before it decays into other particles. how far is this in the rest frame of the pion?

Explanation:

It is given that,

Life time of a pion,

Distance covered by a pion, d = 15 cm = 0.15 m

We need to find distance from the rest frame of the pion. Firstly, we can calculate the speed of the pion as :

v = 5769230.76 m/s

or

Its length in the rest frame is given by the formula as :

or

So, the length of the pion in rest frame is 14.9 cm. Hence, this is the required solution.

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.

i think it would be 5