On a flat surface, a car remains in one place because of gravity

• A. True
• B. False
• C. It depends on speed
• D. Gravity does not affect motion

Answer: (A)

Gravity acts downward and is balanced by the ground with a normal force, so it doesn’t create a horizontal pull to keep the car in place. Whether the car stays still depends on horizontal forces: if there are none, it stays at rest (inertia); if there’s a small push, static friction between the tires and road resists motion up to a limit, and the car only moves if that friction is overcome. So on a flat surface, gravity isn’t what causes the car to remain put; the lack of horizontal force and/or friction stopping motion is what keeps it from moving.