Which quantity is measured in joules — select the correct answer.

✅ D. 3 × 10^8 m/s

Light travels in vacuum at approximately 3 × 10^8 meters per second. Read more

✅ C. Voltmeter

A voltmeter measures potential difference. Read more

✅ D. Refraction

Refraction is the change in direction of light due to a change in speed between media. Read more

✅ B. Newton's third law

Newton's third law describes action and reaction forces. Read more

✅ D. 3 × 10^8 m/s

Light travels in vacuum at approximately 3 × 10^8 meters per second. Read more

✅ A. 9.8 m/s²

Near Earth's surface, gravitational acceleration is approximately 9.8 m/s². Read more

✅ D. 9.8 m/s²

Near Earth's surface, gravitational acceleration is approximately 9.8 m/s². Read more

✅ B. Newton's third law

Newton's third law describes action and reaction forces. Read more