Respuesta :

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