# How to Calculate the Initial energy of two protons colliding

## Homework Statement

Tow protons of equal energy collide head on and the result is

p+p -----> p+p+ Pi0

If all particles produced at rest what must be the KE of the initial protons

## Homework Equations

mass of Pi0 = 135MeV/c2

## The Attempt at a Solution

Total energy of the system, E= mc2

Mass of proton = 1.6726 *10-27 Kg

Hence initial energy = 2* 1.6726*10-27*2.99*108*2.99*108

But in this case why do I need the mass of Pi 0...I guess I am terribly worng pls help

vela
Staff Emeritus
Homework Helper
The initial energy isn't just the sum of the rest energies because the protons are moving.

Hint: Use the 938 MeV/c2 for the mass of the proton. It'll make the calculations simpler — no unit conversions needed.

The initial energy isn't just the sum of the rest energies because the protons are moving.

Hint: Use the 938 MeV/c2 for the mass of the proton. It'll make the calculations simpler — no unit conversions needed.

I didnt get you...could you may be explain a bit more

vela
Staff Emeritus