AQA AS Level Physics Paper 2, June 2022: Question 21

✅ Correct Answer

B: kinetic energy

💡 Key Knowledge

• Scalar: Completely described by magnitude (size) alone (e.g., mass, energy, time, speed).
• Vector: Requires both magnitude and a specific direction to be fully defined (e.g., force, velocity, momentum, displacement).
• All forms of energy (including kinetic energy) are scalar quantities because energy has no directional component.

🧠 Exam Technique

Quickly scan the options and test each one by asking: "Does this quantity make sense with a direction attached?"

• Force: "10 N upwards" (Direction exists ➔ Vector)
• Velocity: "15 ms⁻¹ due East" (Direction exists ➔ Vector)
• Momentum: "50 kgms⁻¹ downwards" (Direction exists ➔ Vector)
• Kinetic energy: "100 J" (Direction makes no sense ➔ Scalar)

❌ Common Errors

• Confusing speed (scalar) and velocity (vector), or mistakenly thinking energy values have directional properties.
• Rushing multiple-choice questions without mentally checking the definitions of all four given options.