63. A 0.50-kilogram ball thrown vertically upward has an initial kinetic energy of 80 J. What are (a) its kinetic and potential energies when it has traveled three-quarters of the distance to its maximum height? (b) its speed at this point? (c) its potential energy at the maximum height (assume a reference is chosen to be zero at the launch point)? (a) 20 J; 60 J (b) 8.9 m/s (c) 80 J