Target Exam

CUET

Subject

Physics

Chapter

Atoms

Question:

An electron of mass $9.11×10^{-31}\, kg$ is moving with velocity $5.4×10^6\, m/s$. Its momentum will be

Options:

$4.92 × 10^{-24}\, kg\, m/s$

$4.66 × 10^{-25}\, kg\, m/s$

$6 × 10^{-37}\, kg\, m/s$

$6.6 × 10^{-22}\, kg\, m/s$

Correct Answer:

$4.92 × 10^{-24}\, kg\, m/s$

Explanation:

The correct answer is Option (1) → $4.92 × 10^{-24}\, kg\, m/s$

Given:

Mass of electron, $m = 9.11 \times 10^{-31} \ \text{kg}$

Velocity, $v = 5.4 \times 10^6 \ \text{m/s}$

Momentum: $p = m v$

$p = (9.11 \times 10^{-31}) \cdot (5.4 \times 10^6) = 4.9194 \times 10^{-24} \ \text{kg·m/s}$

Momentum, $p \approx 4.92 \times 10^{-24} \ \text{kg·m/s}$