Answer: Galileo.
- A Kepler
- B Galileo
- C Archimedes
- D Faraday
Correct answer: B. Galileo
Explanation: Galileo argued that a body on a smooth plane would keep moving forever at constant velocity if no friction acted, which became the basis of Newton's first law (the law of inertia).
Free-body diagram of a block on an incline: weight (mg) resolves into mg sinθ along the slope and mg cosθ into the slope, balanced by the normal force N and friction f.
Concept context
Newton's three laws, friction, circular motion, and free body diagrams.