A missile is fired vertically from a point that is 5 miles from a tracking station and at the same elevation. If the angle of elevation of the missile changes at a constant rate of 2 degrees per second, find the velocity of the missile when the angle of elevation from the tracking station is 30 degrees.

the velocity of the missile when the angle of elevation from the tracking station is 30 degrees =

Explanation:

The method employed in solving this question is to relate it to a right- angled triangle;

Now ; if we consider the missle fired vertically from a point  5 miles from tracking station ; with an angle θ and h becoming the height :

Then ;

Differentiating the above equation ; we have

Replacing ; and ; we have :

Thus,the velocity of the missile when the angle of elevation from the tracking station is 30 degrees =

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2