Which of these quantities needs to have a direction associated with it? select one: a. force only b. force and acceleration c. mass only d. acceleration only

With i really need the correct answer!

The necleus of an atom is made up of what subatomic particles?

10 points! will mark brainiest! in a heat engine if 1,000 j of heat enters the system and the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2,000 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 energy added you so much!