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Newton’s First Law of Motion: The Law of Inertia. Physics Oct 12/15 Chapter 4 Kena Allison. Topic Newton’s 1 st Law . Facts Also called the Law of inertia
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Newton’s First Law of Motion:The Law of Inertia Physics Oct 12/15 Chapter 4 Kena Allison
Topic Newton’s 1st Law Facts Also called the Law of inertia Every object continues in a state of rest, or motion in a straight line at constant speed, unless it is compelled to change that state by nonzero forces exerted upon it. What is Newton’s 1st Law
Topic Put Newton’s 1st Law into your own words Facts Objects in motion stays in motion in a straight line and with the same speed AND objects at rest stay at rest unless an outside force acts upon it. So What?
Topic inertia Facts Property of a body/object to resist change Think of it as an object’s laziness If an object is at rest, then it is too “lazy” to move If an object is in motion, then it is too “lazy” to stop Mass is how we measure inertia (kg) Why is it called the Law of Inertia?
A video on the 1st Law • Newton's First Law Explained
Topic mass Facts The amount of matter/inertia an object has If an object has more mass, then it has more inertia (more laziness) Symbol is m The units are kilograms (kg) Let’s take a closer look at mass
Now Apply These Concepts Task Explain how a table cloth can be removed from under a plate without the plate moving Explanation The plate does not move because it has inertia and according to Newton’s 1st Law since the plate is at rest, it wants to stay at rest. The outside force is only applied to the cloth, not the plate.
Topic Force Facts Any push or pull Vector quantity Symbol is F Units are Newtons (N) What might cause an object to change its state?
Reach for the Stars • What are the units for friction force? Newtons (N) All forces have Newtons (N) as their units
What might cause an object to change its state? Topic FrictionForce Facts Force that acts between materials that touch as they move past each other that SLOWS or STOPS MOTION. Caused by irregularities in surfaces of objects that are touching
What might cause an object to change its state? Topic Net Force Facts The combinations of forces being applied Show with vectors
Equilibrium Rule • When the net force is zero, an object is in equilibrium • No motion (static equilibrium) • Motion in straight line with constant speed (dynamic equilibrium)
Let’s Take a Closer Look at a specific type of Force Topic Normal force Facts Also called support force Upward Force Opposite force of gravity
Topic weight Facts The force of gravity on an object WEIGHT IS NOT MASS!!! Weight equals mass times gravity w = mg Let’s Take a Closer Look at a specific type of Force
Newton’s 1st Law Relates to Real-World Safety • Seatbelts and Headrest
Task According to the law of inertia, why is it important to have seatbelts in cars? Why headrest? Explanation Closing