Kinematics
ID: #1048 | Difficulty: easy
AI Quick Answer:
The correct option for this defence exam question is (A) which is 1440 J. Detailed proof and explanation are supplied below.
Calculate the kinetic energy of an object having a mass of 20 kg moving with a uniform velocity of 12 m/s.
Key Takeaways for NDA & CDS Candidates
- Ensure you recall the standard formulas for Kinematics during UPSC exam preparation.
- Eliminating obviously incorrect choices based on dimensional analysis or limits saves valuable seconds.
- Expert tip: Written defence mock tests should be practiced weekly with strict negative marking rules.
Correct Answer: (A)
1440 J
Step-by-Step Explanation
The formula for Kinetic Energy (KE) is:
KE = \frac{1}{2} m v^2
Given:
Mass (m) = 20 kg
Velocity (v) = 12 m/s
Substituting the values:
KE = \frac{1}{2} \times 20 \times (12)^2
KE = \frac{1}{2} \times 20 \times 144 = 1440 Joules (J).
KE = \frac{1}{2} m v^2
Given:
Mass (m) = 20 kg
Velocity (v) = 12 m/s
Substituting the values:
KE = \frac{1}{2} \times 20 \times (12)^2
KE = \frac{1}{2} \times 20 \times 144 = 1440 Joules (J).
| Question Metadata Summary | |
|---|---|
| Exam Category | UPSC NDA / CDS / AFCAT / Agniveer |
| Subject Unit | NDA Physics Questions |
| Sub-topic / Module | Kinematics |
| Correct Option | Option (A) |
| Target Year | UPSC Defence Exams 2026 |