Question

Q.Rain is falling vertically with a speed of 35m/s. A women rides a bicycle with a speed of 12 m/s in east to west direction. In which direction should she hold her umbrella?

Answer 1

Wind is blowing in the direction from east to west direction and the direction of the rain is from east to west. The resultant direction of rain is to find the vector sum of both the vectors.

now, the resultant velocity is given as

R = ((35)2 + (12)2)1/2

or

R = 37 m/s

the direction of this resultant will be

tanθ = 12/35

or

θ = 19 degrees

so,

the woman should hold hers umbrella at an angle of 19 degree with the vertical or the direction of rainfall.

Answer 2

velocity of rain = 35 m/ sec
velocity of Woman = 12 m / sec
velocity of woman with respect to rain is
√(12^2 + 35^2).= 37 m / sec
and the angle between them is 71°
and the direction is 71° above the west direction