Chapter 3, Problem 22P

To determine

Time required for football to hit ground.

Answer to Problem 22P

2.07 sec.

Explanation of Solution

Given:

The initial speed of football is 18 m/s and it makes an angle of 35° with ground.

Formula Used :

The time of flight of football is,

  $T=\frac{2u\sin \theta }{g}$

Calculation :

  $\begin{array}{l}\text{Initial speed, }u\text{ = 18 m/s}\\ \text{Angle,}\theta \text{ =}\text{35°}\end{array}$

Substituting the values

  $\begin{array}{c}T=\frac{2\times 15\times \sin \left(35\right)}{10}\\ =2.07\text{sec}\end{array}$

Conclusion :

Thus, the time required for football is 2.07 sec.