Newton’s Laws of Motion
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Slide 1 - Newton’s Laws of Motion
- By: Ishaan Chainani
- Physics is all about motion – why things move and how they move
- Isaac Newton; a scientist who lived in the 17th century, discovered the 3 laws of motion
- The first law is also called the law of inertia.
- But what is inertia?
- This couch won’t move unless a force acts on it i.e. this couch is ‘lazy’.
- Scientists call this laziness of an object its inertia.
- Newton summarized this law as:
- An object continues to stay at rest
- Or continues in uniform motion
- In a straight line
- Unless an unbalanced force acts on it
- Newton then went on to explain why it takes more force to move heavier objects
- If you are pushing a truck down the street, you are going to need a significant amount of force to do so.
- However you will need barely any force to push a tricycle down the street.
- Newton summarized this as the second law of motion:
- Acceleration is produced
- when a force acts on a mass.
- The greater the mass (of the object being accelerated),
- the greater the amount of force needed ( to accelerate the object).
- Mathematically speaking
- Acceleration = Force/Mass or a = F/m
- Finally Newton looked at how objects react
- The exhaust coming out of the bottom of a rocket, makes it shoot up.
- The exhaust pushing against the earth is the action
- The earth reacts by pushing back and lifting up the rocket
- Newton summarized this as the third law of motion:
- For every action,
- There is an equal and opposite
Slide 17 - Were you paying attention?