JEE Main2018PhysicsCenter of Mass, Momentum and CollisionActual
The mass of a hydrogen molecule is 3.32 × 10 - 27 kg . If 10 23 hydrogen molecules strike, per second, a fixed wall of the area 2 cm 2 at an angle of 45 o to the normal, and rebound elastically with a speed of 10 3 m s - 1 , then the pressure on the wall is nearly:
Options
- A4.70 × 10 2   N   m - 2
- B2.35 × 10 3   N   m - 2
- C4.70 × 10 3   N   m - 2
- D2.35 × 10 2   N   m - 2
Correct answer
B. 2.35 × 10 3   N   m - 2
Step-by-step solution
F = 2 m n V c o s θ ⇒ P = 2 m n V c o s θ A ⇒ P = 2 × 3.32 × 10 - 27 × 10 23 × 10 3 2 × 2 × 10 - 4 ⇒ P = 2.35 × 10 3   N   m - 2