Question # A man walks in rain with a velocity of ( 5 mathrm{kmh}^{-1} ). The rain drops strike at him at an angle of ( 45^{circ} ) with the horizontal. The velocity of the rain if it is falling vertically downward is:

# A man walks in rain with a velocity of ( 5 mathrm{kmh}^{-1} ). The rain drops strike at him at an angle of ( 45^{circ} ) with the horizontal. The velocity of the rain if it is falling vertically downward is:

( (A) 5 mathrm{kmh}^{-1} )

(B) ( 4 mathrm{kmh}^{-1} )

(C) ( 3 mathrm{kmh}^{-1} )

(D) ( 1 mathrm{kmh}^{-1} )

Solution

[

begin{array}{l}

S=x cos 45^{circ}

S=frac{x}{sqrt{2}}

x=5 sqrt{2}

end{array}

]

rentical velocity: ( frac{x sin 45}{5 sqrt{2} times frac{1}{8}}=515 mathrm{m} / mathrm{h} )