Physics
Thinking Motion Requires a Continuous Force
Students think an object must have a continuous force on it to keep moving at constant speed.
Quick check
Why students make it
Everyday experience makes motion seem like it needs constant pushing because friction and air resistance usually slow objects down. Students mistake the force needed to overcome friction for a force needed to maintain motion itself.
The rule done right
An object with zero net force keeps moving at constant velocity. A net force is needed to change velocity, so and constant velocity means .
Related resources
-
Newton's First Law Infographic -
Newton's Second Law Infographic -
Newton's Laws of Motion Infographic -
Physics, Equilibrium of Forces Infographic -
Distance-Time & Velocity-Time Graphs Infographic - Newton's Laws & Forces Cheat Sheet
- Free Body Diagrams Reference Cheat Sheet
- Kinematics Equations Cheat Sheet
- Friction, Normal Force & Inclined Planes Cheat Sheet
- Vectors in Physics Cheat Sheet
- Science, Newtons Laws of Motion Worksheet
- Physics, Newton's Laws, Free Body Diagrams and Net Force Worksheet
- Science, Free Body Diagrams Worksheet
- Kinematics, Velocity, Acceleration, and Motion Graphs Worksheet
- Physics, Kinematics, Velocity-Time and Position-Time Graphs Worksheet
- Forces & Free-Body Diagram Tool Tool
- Kinematics Solver Tool
- Vector Addition & Components Explorer Tool
- AP Physics FRQ Simulator Tool
- Balanced Forces Lab Lab
- Atwood Machine Lab Lab
- Action-Reaction Lab Lab
- Graph Analysis Lab Lab