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 =

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.