Welcome to this physics lecture on Dynamics! In this video, we explore specific categories of everyday forces, focusing on normal force and tension.
We will break down exactly what a normal force is, explaining how surfaces—even seemingly rigid ones like tables—deform slightly under a load to exert an upward, perpendicular restoring force. We will also tackle the classic physics problem of an object resting on an incline. You will learn how to use trigonometry to resolve the force of gravity into parallel and perpendicular components to calculate the exact acceleration of a skier racing down a slope. Plus, we will clear up the common and confusing mistake of mixing up the variable for normal force (N) with the unit for newtons (N).
Next, we explore tension—the pulling force transmitted through flexible connectors like ropes, cables, and even the tendons in your fingers. We will prove the old saying that "you can't push a rope," and show you how to calculate the massive tension forces supporting a tightrope walker. You will see exactly why pushing perpendicular to a flexible connector creates massive tension, a trick you can even use to pull a stuck car out of the mud!
Finally, we will briefly touch on the difference between real forces with physical origins and fictitious forces that only appear because an observer is in an accelerating or rotating system, like Earth
. Whether you are studying for college physics or just want to master the math behind everyday forces, this video will give you the foundational tools you need to succeed.
