Question 9 of 10intermediate🔧 ApplyNumerical4 marks

What is the de Broglie wavelength of (a) a bullet of mass 0.040 kg travelling at the speed of 1.0 km/s, (b) a ball of mass 0.060 kg moving at a speed of 1.0 m/s, and (c) a dust particle of mass 1.0×1.0 \times 10^{-9}$$ kg drifting with a speed of 2.2 m/s?

(a)
Answer

1.66×101.66 \times 10⁻³⁵ m

(b)
Answer

1.11×101.11 \times 10⁻³² m

(c)
Answer

3.01×103.01 \times 10⁻²⁵ m

Explanation

This question tests application of the de Broglie relation λ = h/p = h/(mv). The context shows similar calculations in Example 11.3 for an electron and a ball. For macroscopic objects, the de Broglie wavelengths are extremely small (10⁻³² to 10⁻³⁵ m), far beyond experimental measurement, explaining why wave properties are not observed in daily life. Only subatomic particles have measurable de Broglie wavelengths.

PreviousNext