What is the kinetic energy of a single He atom traveling at 2.0 × 10⁴ m/s?

Question

Quizplus · Accepted Answer

The kinetic energy (KE) of an object is given by the formula KE = 1/2 mv^2, where m is the mass and v is the velocity. The mass of a helium atom is approximately 4.002602 u (atomic mass units), which is about 4.002602 × 1.660539 × 10^-27 kg = 6.646 × 10^-27 kg. Using the given velocity of 2.0 × 10^4 m/s, the kinetic energy is calculated as KE = 1/2 (6.646 × 10^-27 kg) × (2.0 × 10^4 m/s)^2 = 1.3 × 10^-21 J, which matches choice A when considering significant figures and unit conversion.

What Is the Kinetic Energy of a Single He Atom