For this case we have the following equation: H (t) = - 16t ^ 2 + 28t When the dolphin finishes a jump, then the height is equal to zero. We have then: -16t ^ 2 + 28t = 0 We look for the roots of the polynomial: t1 = 0 t2 = 1.75 s Therefore, the dolphin takes 1.75 seconds to make a jump. Answer: it will take for the dolphin to make one jump about: t = 1.75 s
