1) The grapefruit is in free fall, so it moves by uniformly accelerated motion, with constant acceleration 
. Calling h its height at t=0, the height at time t is given by
We are told thatn when
the grapefruit hits the ground, so h(0.75 s)=0. If we substitute these data into the equation, we can find the initial height h of the grapefruit:
2) The speed of the grapefruit at time t is given by
where
is the initial speed of the grapefruit. Substituting t=0.75 s, we find the speed when the grapefruit hits the ground:
We are told thatn when
2) The speed of the grapefruit at time t is given by
where