Two Cart Race

About this simulation

Two Cart Race puts Newton's Second Law to the test in a head-to-head competition. Set the mass and applied force for each of two carts, then hold the spacebar to watch them accelerate down the track. The cart with the greater acceleration — determined by F = ma — reaches the finish line first.

By independently controlling force and mass for each cart, you can isolate either variable and observe its effect on acceleration. Race identical masses with different forces, or equal forces with different masses, to build a concrete intuition for why Newton's Second Law works the way it does.

Learning Goals

• Predict which cart will win by calculating acceleration from force and mass before starting the race
• Describe the relationship between net force and acceleration when mass is held constant
• Describe the relationship between mass and acceleration when force is held constant
• Explain why a heavier cart with the same applied force accelerates more slowly than a lighter one
• Use F = ma to quantitatively compare two scenarios simultaneously

How to Use

• Use the sliders or input fields to set the mass and force for Cart A and Cart B
• Before racing, predict which cart will win based on a = F / m
• Hold the spacebar (or press the Push button) to apply force and start the race
• Observe the force arrows: longer arrows mean more force
• Reset and try different combinations — same force, different mass; same mass, different force