Physics of Bumper Cars

Written by Carly Hallman

Bumper cars have been a source of amusement and fascination for the young and young at heart for generations. Stepping into a bumper car, strapping oneself in, and letting loose on the other drivers is a pastime that continues to gain fans to this day. Surprisingly, this incredibly fun electric car ride has its roots in hard science. In some circles, bumper cars are considered a great real-world example of Newton’s Laws of Motion. Thankfully, understanding Newton’s laws is as easy as watching bumper-car drivers crash and burn rubber.

Newton’s Laws of Motion

When it comes to bumper cars, Newton’s laws are the driving force behind much of the fun that you have at amusement parks. Newton’s first law, the law of inertia, covers how objects move when they’re in motion. This law says that objects that are moving stay in motion unless they’re influenced by an outside force, and the same holds true for objects that are at rest. The law of acceleration, Newton’s second law, states that an object’s mass and the force applied to it will influence how much the object moves. Under this law, it’s understood that bigger objects take more force to move than smaller objects and when more force is applied, more acceleration can be witnessed. Lastly, Newton’s third law, the law of interaction, simply states that every action can be expected to produce an equal and opposite reaction. This law especially is what can give a bumper car its trademark jolts of fun.

  • Bumper Cars: The University of Virginia gives an academic overview of bumper cars and the physical forces that guide their movements and trajectories.
  • Amusement Park Physics (PDF): Utah State University provides examples of how various amusement park and carnival rides illustrate known physical laws.
  • Newton’s Laws of Motion: The National Aeronautics and Space Administration (NASA) gives a brief summary of Newton’s Laws of Motion and provides educational activities for all grade levels.

Bumper-Car Mechanics

Though in the real world, collisions can mean serious accidents or injuries for people in vehicles, bumper cars are created with special rubber linings on the outsides of the cars to protect against damage. These rubber linings are what soften the impact and help the cars bounce off of each other. While electrical energy drives the cars to collide with each other, the rubber acts as a special barrier between cars, which can alter movement and angles of impact. In some cases, the rubber lining will readjust the direction of the bumper car to create an entirely new trajectory.

  • Momentum and Collisions: The University of Louisville Department of Physics discusses momentum and collisions and illustrates the concepts using mathematical equations.
  • Conservation of Momentum: Saint Ignatius High School illustrates the conservation of momentum using easy-to-understand illustrations.
  • Types of Collisions: The University of Alaska Fairbanks discusses different types of collisions and how they are affected by basic laws of physics.

Momentum, Impulse, and Collisions

Several different variables can influence how someone will experience driving a bumper car and colliding into another. The two cars’ masses, the weights of the drivers, and the velocities at which each is traveling can affect how each car and driver reacts after a collision. If the two people in the cars have different masses, the larger driver will move around less upon impact. Similarly, the driver who is traveling fastest will move the other car more when contact is made.

  • Energy, Momentum and Driving: Indiana University-Purdue University Indianapolis details the forces of energy and momentum while driving.
  • A Guide to Momentum and Collisions (PDF): An excerpt from a textbook helps detail the concept of momentum during various types of collisions.
  • Impulse and Momentum: The Codman Academy Charter Public School discusses impulse and momentum during crashes, provides demos, and gives a list of resources for further information.

Safety and Fun

Driving bumper cars can almost always guarantee a great time. The law of inertia, however, can have a negative effect on drivers who don’t follow basic safety rules and wear seat belts in bumper cars. This is because the body of a driver will keep moving in the way it was initially moving upon impact, which can result in the driver possibly being thrown from a bumper car if they aren’t properly restrained. Much like when driving in a vehicle on a street, it’s important to buckle up and prepare oneself for bumps along the road.