4.24. A fighter plane is flying horizontally at an altitude of 1.5 km with a speed of 720 km/h. At what angle of sight when the target is seen, should the pilot drop the bomb in order to attack the target?


Hint: Time is taken to travel horizontal and vertical distances will be the same.
Step 1: Draw the diagram.

Consider the adjacent diagram. Let a fighter plane, when it be
at position P, drops a bomb to hit a target T.

Step 2: Calculate the time taken to travel vertical distance.

Altitude of the plane (P'T) = 15 km = 1500 m

P'T=12gt21500=12×9.8t2t2=15004.9t=150049=17.49s

Step 3: Write the equation in the horizontal direction and calculate PP'
Speed of the plane =720km/h=720×518m/s=200m/s

If the bomb hits the target after time t, then the horizontal distance traveled by the bomb.
                           PP' = vxt = 200t

PP'=200×17.49mNow,tanθ=P'TP'P=1500200×17.49=.49287=tan2312'θ=2312'.