A ball is thrown vertically upwards. It returns 6s later. Calculate:(i) the greatest height reached by the ball, and (ii) the initial velocity of the ball. (Take g=10ms⁻²)
a.(i) 40m, (ii) 30ms⁻¹
b.(i) 45m, (ii) 30 ms⁻¹
c.(i) 45 m, (ii) 60 m s⁻¹
d.(i) 45 m, (ii) 20 m s⁻¹