What is the molarity of a solution that contains 50.0g of NaOH (molar mass = 40 grams/mole) in 2.0L of solution?

Suppose the universe were completely empty except for one object-a solid sphere moving through space of 100 km/s. what sort of path would the object be moving in? explain your answer

May someone me with these science questions

In a heat of an engine, if 700 j enters the system, and the piston does 400 j of work what is the final internal (thermal) energy of the system if the initial energy is 1,500 j