What units are used to measure mass?

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

In a good thermo flask the main cause of heat loss is

Will mark as brainliest how does a catapult increase the trajectory of an object? ps. answer as if u were a 5th grader