Question

A plane is flying horizontally at a height of 5000 m with a speed of 500 m/s. At time t = 0 a bombshell is fired from a point on the ground exactly below the plane, at angle $\theta$ from the horizontal. The bombshell hits the plane in 10 seconds. What is the value of cot $\theta$?

Answer 1

In 10 seconds, plane would have moved 500X10=5000m horizontally. Also, bombshell has travelled that much distance horizontally. Thus, from geometry, we see that $tan\theta =\frac{H}{Distance}=\frac{5000}{5000}=1$. Thus, $cot\theta =1$ or $11/2cot\theta =5.5$