From Masseffect 2
This, recruits, is a 20-kilo ferrous slug. Feel the weight. Every five seconds, the main gun of an Everest-class dreadnought accelerates one to 1.3 percent of light speed. It impacts with the force of a 38-kiloton bomb. That is three times the yield of the city-buster dropped on Hiroshima back on Earth. That means Sir Isaac Newton is the deadliest son-of-a-b*tch in space. Now! Serviceman Burnside! What is Newton's First Law?
Sir! An object in motion stays in motion, sir!
No credit for partial answers, maggot!
Sir! Unless acted on by an outside force, sir!
Damn straight! I dare to assume you ignorant jackasses know that space is empty. Once you fire this hunk of metal, it keeps going till it hits something. That can be a ship, or the planet behind that ship. It might go off into deep space and hit somebody else in ten thousand years. If you pull the trigger on this, you are ruining someone's day, somewhere and sometime. That is why you check your damn targets! That is why you wait for the computer to give you a damn firing solution! That is why, Serviceman Chung, we do not "eyeball it!" This is a weapon of mass destruction. You are not a cowboy shooting from the hip!
Sir, yes sir!