When you are driving, the force of gravity...

• A. always works against you
• B. can work against you or in your favor
• C. never affects motion
• D. only affects objects in air

Answer: (B)

Gravity pulls downward toward the center of the Earth, and its effect on a moving car depends on the direction of motion. On a slope, gravity has a component along the surface that can either help you move downhill or hinder you when going uphill. If you’re going downhill, gravity adds to your forward force, increasing speed unless you brake or use the engine to control it. Going uphill, gravity pulls backward along the slope, making it harder to climb and requiring more power or more braking to control speed. On level ground, gravity mainly affects the weight of the car, which changes the friction available for braking and turning; more weight can increase traction up to a point, aiding control. In short, gravity can work against you or in your favor depending on the situation.