1. The problem statement, all variables and given/known data You fly 5000 km across the United States on an airliner at 250 m/s. You return two days later traveling at the same speed. How much less have you aged more then your friends at home. 2. Relevant equations I think the time dilation equation is used: delta_t= delta_t'/ sqrt(1-beta^2) where beta= v/c 3. The attempt at a solution I have the solution from the solution manual but i'd like to know how they got to the answer, 1.39×10−8 s. to find the delta t is the equation delta_t=delta_x/v used? the beta is (250m/s)/(3.0*10^(8) m/s ) i keep getting 1.7 *10^-5 although the solution manual says this is incorrect. Any advice is appreciated!