A girl standing on road holds her umbrella at 45° with the vertical to keep the rain away. If she starts running without umbrella with a speed of 15 √2 kmh -1, the rain drops hit her head vertically. The speed of rain drops with respect to the moving girl is :

Question

A girl standing on road holds her umbrella at 45° with the vertical to keep the rain away. If she starts running without umbrella with a speed of 15 √2 kmh -1, the rain drops hit her head vertically. The speed of rain drops with respect to the moving girl is : (A) 30 k m h-1 (B) (25/√2) k m h-1 (C) (30/√2) k m h-1 (D) 25 km h -1

Tardigrade Admin · Accepted Answer

<img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/ee3bea7dd672292aa477b6269335fc63-.png" /> V = tan θ=(VG/VR G) 1=(VG/VR G) ⇒ 15 √2=VR G

Q. A girl standing on road holds her umbrella at $4 5^{\circ}$ with the vertical to keep the rain away. If she starts running without umbrella with a speed of $152 km h^{- 1}$ , the rain drops hit her head vertically. The speed of rain drops with respect to the moving girl is :

$30 km h^{- 1}$

$\frac{25}{2} km h^{- 1}$

$\frac{30}{2} km h^{- 1}$

$25 km h^{- 1}$

$V = tan θ = \frac{V _{G}}{V _{RG}}$
$1 = \frac{V _{G}}{V _{RG}} \Rightarrow 152 = V_{RG}$

Q. A girl standing on road holds her umbrella at 45∘ with the vertical to keep the rain away. If she starts running without umbrella with a speed of 152​kmh−1, the rain drops hit her head vertically. The speed of rain drops with respect to the moving girl is :

30kmh−1

2​25​kmh−1

2​30​kmh−1

25kmh−1