Essential Question

How do the laws of conservation of energy and momentum govern interactions between objects, from everyday collisions to planetary orbits?

What You Will Learn

• 1Calculate centripetal acceleration and force for circular motion.
• 2Apply Newton's law of universal gravitation to orbits and escape velocity.
• 3Use conservation of momentum to analyze elastic and inelastic collisions.
• 4Calculate work, kinetic energy, potential energy, and power.
• 5Apply the work-energy theorem and conservation of mechanical energy.
• 6Explain Einstein's postulates and the consequences of special relativity.

Why It Matters

Conservation laws are among the most powerful tools in physics. They let engineers design roller coasters, physicists predict particle collisions, and astronomers calculate orbital paths — all without tracking every force at every instant.