1. The problem statement, all variables and given/known data Antihydrogen is the only antimatter element that has been produced in the laboratory, albeit just a few atoms at a time. Each antihydrogen atom consists of a positron in orbit around an antiproton and has the same atomic mass as hydrogen. If an antihydrogen atom collides with a hydrogen atom, they annihilate each other and create gamma radiation. If this energy could be harnessed in a matter-antimatter automobile engine, how far could a car travel on 10 mg each of antihydrogen and hydrogen? At highway speeds, a typical automobile expends about 2.5×10^3 J per meter. 2. Relevant equations E = mc^2 3. The attempt at a solution I know the answer is 9.00 * 10^8 m, but I haven't been able to work out an answer that is even close to this. I've solved the minimum amount of energy that is released in this process (3.01 * 10^-10 J). I'm not sure if this is relevant, but I solved it if necessary.