# Sir Isaac Newtons Three Laws of Motion Newtons

• Slides: 11

Sir Isaac Newton’s Three Laws of Motion

Newton’s First Law of Motion “ Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it. ” Which Means: An object in motion tends to stay in motion, and an object at rest tends to stay at rest, unless the object is acted upon by an outside force

Newton’s First Law of Motion Newton’s first law = inertia Objects at rest remain at rest. This means that if a rock is in motion and nothing at all is pushing on it or pulling on it, then it will continue in a straight line forever (or until something pushes on it). We usually don’t notice the effects of Newton’s first law on earth because the atmosphere and the air, will eventually slow down any moving objects. In space moving objects will obey Newton’s first law because there is no air or atmosphere. A lot of inertia! Since the train is so huge, it is difficult to move the train from rest. Very little inertia. Since the baby carriage is so small, it is very easy to move from rest.

Newton’s Second Law of Motion “The acceleration of an object is in the same direction of the externally applied force and is directly proportional to the magnitude of force applied as well as inversely proportional to the mass of the object. ” Which Means: Acceleration = Force Mass Acceleration = the rate at which velocity changes Ø Velocity is measured in meters per second (m/s) Ø Acceleration is usually measured in meters per second squared (m/s 2) Ø Force is expressed in Newtons (N) Ø

Newton’s Second Law of Motion Ø The second law governs all acceleration Ø Acceleration is produced when a force acts on a mass Ø The greater the mass (of the object being accelerated), the greater amount of force needed (to accelerate the object)

Newton’s Second Law of Motion Joe makes the 1000 kg car accelerate at. 05 m/s 2 Ø Using Newton’s 2 nd law you can compute how much force Joe is applying to the car. Ø

Newton’s Second Law of Motion Ø Using the equation: Force = Mass x Acceleration (1, 000 kg x. 05 m/ s 2) You would get the answer of 50 N Ø Answer: Joe is applying 50 Newtons of force to the car.

Newton’s Third Law of Motion “For every force imposed, there is an equal and opposing force in reaction, so as the Earth’s gravity pulls on the Moon, the Moon pulls back on the Earth with an equally strong force. ” Which means: Every action has an equal and opposite reaction (actions = forces)

Newton’s Third Law of Motion Ø We feel the third law every time we interact with other surroundings. Ø For example when you punch someone in the face you know that your hand applies a force to the person’s face, but the person’s face also applies a force to your hand. Usually, the reason it hurts the face more than the hand is because the face is softer than the hand.

Newton’s Third Law of Motion #1 #2

The End Thanks for your Attention!!!!