An 18-year-old runner can complete a 10.0-km course with an average speed of 4.46 m/s. A 50-year-old runner can cover the same distance with an average speed of 3.91 m/s. How much later (in seconds) should the younger runner start in order to finish the course at the same time as the older runner?

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final