I hope the picture helps :)
Answer:
At time t = 0.408 sec diver will be at maximum height
Step-by-step explanation:
We have given equation of the height 
We know that velocity is the rate of change of distance with respect to time
So 
At maximum height velocity will be zero
So 
t = 0.408 sec
So at time t = 0.408 sec diver will be at maximum height
Answer:
Q (-4, -2); 2 units; Q' will be above the x-axis; 2 unites; no; yes, the y coordinates are multiplied by -1; Q' (-4, 2); R' (-2, 2), S' (1, 5), T' (-2, 5);
Step-by-step explanation:
even after a reflection over the x-axis, each points distance from the x-axis will stay the same
the x-coordinates don't change because the distance from the y-axis stays the same
the picture below shows points of Q'R'S'T', just connect the vertices