Practical Application All things being equal, a car with lightweight rims will accelerate faster than a car with heavy steel rims. Real World Examples A race car’s mass changes during a race because fuel is being used as the car goes around the track. Challenge Yourself Ride a mountain bike with wide tires and then ride a racing bike with really thin tires and notice the difference in acceleration due to distribution of mass. The mass of the wheels in this exhibit are the same. The key is where the mass is located on each wheel. Did You Know ? AT HOME EXPERIMENT Exhibit Key Concept Distribution of Mass