1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution So for part a, i just plugged 3 into the equation, got the U(3) = -5.36 to get mechanical energy, (KE + PE): 5 J + (-5.36 J)= -0.36 J is this correct? what does it mean when the total energy is a negative value? (I have never seen this before) and part b) I have no clue how to do this.