Density is mass per unit volume
remember
p= m/v where v is vol, m is mass and p is density
A baseball traveling at 100 mph has more kinetic energy than a baseball traveling at 50 mph because the kinetic energy = 1/2 x mass x velocity. Since the baseballs should have the same mass, the velocity is what will determine which ball has more kinetic energy. Since the 100 mph baseball has a higher velocity than the 50 mph baseball, it has more kinetic energy.
Medium stars become dwarf stars, large stars become either neutron (pulsar) stars or black holes
