A jet of water with cross section of 6 cm 2 strikes a wall at an angle of 60° to the normal and rebounds elastically from the wall without losing energy. If the velocity of the water in the jet is 12 m / s, the force acting on the wall is

Question

A jet of water with cross section of 6 cm 2 strikes a wall at an angle of 60° to the normal and rebounds elastically from the wall without losing energy. If the velocity of the water in the jet is 12 m / s, the force acting on the wall is (A) 0.864 Nt (B) 86.4 Nt (C) 72 Nt (D) 7.2 Nt

Tardigrade Admin · Accepted Answer

<img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/a9bfce9650479509a8311f5dde34829a-.png" /> (d m/d t)=ρ A v Δ P=F text avg ⋅ 1 sec. ⇒ 2 ρ A v2 cos 60° ⇒ 1000 × 6 × 10-4 ×(12) × (1/2) × 2 =86.4 Nt .

Q. A jet of water with cross section of $6 c m^{2}$ strikes a wall at an angle of $6 0^{\circ}$ to the normal and rebounds elastically from the wall without losing energy. If the velocity of the water in the jet is $12 m / s$ , the force acting on the wall is

0.864 Nt

86.4 Nt

72 Nt

7.2 Nt

$\frac{d m}{d t} = ρ A v$
$Δ P = F_{avg} \cdot 1 sec .$
$\Rightarrow 2 ρ A v^{2} cos 6 0^{\circ}$
$\Rightarrow 1000 \times 6 \times 1 0^{- 4} \times (12) \times \frac{1}{2} \times 2$
$= 86.4 Nt .$

Q. A jet of water with cross section of 6cm2 strikes a wall at an angle of 60∘ to the normal and rebounds elastically from the wall without losing energy. If the velocity of the water in the jet is 12m/s, the force acting on the wall is