An empty cylindrical barrel is open at one end and rolls without slipping straight down a hill. The barrel has a mass of 23.0 kg, a radius of 0.533 m, and a length of 0.800 m. The mass of the end of the barrel equals a third of the mass of its side, and the thickness of the barrel is negligible. The acceleration due to gravity is =9.80 m/s2. What is the translational speed f of the barrel at the bottom of the hill if released from rest at a height of 21.0 m above the bottom?