In a heat engine, if 500 j of heat enters the system, and the piston does 300 j of work, what is the final internal (thermal) energy of the system if the initial energy is 1500 j ?

Plss anybody know how to do this? ? i need the answers from a through d

Four objects each with charge +2.0×10−7c are located at the corners of a square whose sides are 2.0 m long. part a what quantities can be determined using this information? check all that apply. the electric force on a charged object placed at the center of the square. the mass of each object. the total electric potential energy of the system consisting of the four charged objects. part b find the electric force on a charged object placed at the center of the square.

Suppose you plot the distance traveled by an object at various times and you discover that the graph is not a straight line. what does this indicate about the object's acceleration?