Question

The mass of an H₂ molecule is 3.32×10⁻²⁷ kg. If 10²³ hydrogen molecules per second strike 2 cm² of a wall at an angle of 45° with the normal while moving at a speed of 10⁵ cm/s, the pressure exerted on the wall is nearly:

• A. \(1350\,\text{N/m}^2\)
• B. \(2350\,\text{N/m}^2\)
• C. \(3320\,\text{N/m}^2\)
• D. 1660N/m²

Hint:

Pressure equals rate of change of normal momentum per unit area.

Answer 1

The Correct Option is B

Step 1: Change in momentum per molecule: Δ p = 2mv\cos45°
Step 2: Force: F = N Δ p
Step 3: Pressure: P = (F)/(A) ≈ N/m²