A car runs along a horizontal straight road at a speed of 20 m/sec. A person in it observes the rain hitting his car at 60° to the vertical. If the rain is actually falling vertically, the speed of the raindrops is nearly:  

CONCEPT:

• Velocity is the rate of change of displacement of the body and is given by

\(\Rightarrow V = \frac{dx}{dt}\)

Where dx = Rate of change in position, dt = change in time

EXPLANATION:

From the triangle

\(\Rightarrow tan 60^{0} = \frac{V_{c}}{V_{R}}\)

\(\Rightarrow V_{R} = \frac{V_{C}}{tan 60^{0}}\)

\(\Rightarrow V_{R} = \frac{20}{\sqrt{3}} = 11.55 m/sec\)

• Hence, option 2 is the answer