$5.$A ball is $$thrown upwards over the edge of$$a$120$m $$cliff with an $$initial velocity of$25$ms$.$Its height, in $$metres$,$after t $$seconds before it $$hits the ground is $$given by$$h$($t$)=120+25$t$-5$t$2.$

determine the maximum height reached by the ball

determine the velocity of the ballat the instant it hits the ground near the base of the cliff