in a vacuum a scientist drops both a hammer and a feather from the same height compare the speed from the objects as they fall

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

If element x has 99 protons how many electrons does it have

Give one example to show that when substances are mixed,it may result in a chemical or a physical change depending on the conditions.