Answer: Inertia of motion.
- A Gravity
- B Friction
- C Inertia of motion
- D Normal force
Correct answer: C. Inertia of motion
Explanation: Passengers' bodies tend to continue moving forward due to their inertia of motion when the bus decelerates.
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.