7. A projectile is fired from a cliff 200 meter above the water at an inclination of 0
45
to the horizontal, 5
with a muzzle velocity of 100 meter/second. The height h of the projectile above the water is modeled by
 
 
200
100
32
2
2
 

 x
x
h x
where x is the horizontal distance of the projectile from the face of the cliff.
(a) At what horizontal distance from the face of the cliff is the height of the projectile a maximum?
(b) Find the maximum height of the projectile.
(c) At what horizontal distance from the face of the cliff will the projectile strike the water?
(d) When the height of the projectile is 50 meter above the water, how far is it from the cliff?