Physics “If I have seen further, it is by standing on the shoulders of Giants” -Sir Isaac Newton

Physics Formulas Distance= speed x time or d= s · t Speed= distance over time or Speed= d t The formula for finding acceleration is: acceleration = final velocity – initial velocity time Force = mass x acceleration or F = ma Momentum (symbolized by the letter P) is the product of an object’s mass(m) and velocity(v) or :P = m v

Sir Isaac Newton Newton has been regarded as a founding father of modern physical science. Among other great contributions to Science, two of his greatest contributions are the 3 laws of motion and his universal law of gravity

“May the forces be with you!” Force- a push or pull that effects matter. Forces can start, stop, or change the direction of an objects motion. Newton- Force is measured in newtons. One newton is the force necessary to move a one-kilogram mass with an acceleration of one meter per second squared. List 5 examples of forces you have exerted between last period and now…

Newton’s 1 st Law of Motion 1 st Law of Motion: The Law of Inertia: as long as the forces on an object balance each other, the object’s motion will not change. “If an object is at rest, it will remain at rest and if an object is in motion it will not change it’s velocity…until an outside force acts upon it!”

1 st Law of Motion (continued) Balanced forces- when all forces acting on an object are equal and cancel each other out. (ex., barbell, book)

Velocity- the measure of both speed and direction of the motion of an object. Constant velocity- an object will not change it’s velocity as long as the forces acting on it are balanced.

Newton’s 2 nd Law of Motion When the unbalanced forces act on an object, the object will accelerate in the direction that the greater force points! An unbalanced force-when the forces acting on an object are not equal and do not cancel each other out. This causes the object to accelerate. Accelerate- any change in motion! Ex) slow down, speed up, change direction.

Friction- the force that occurs when two surfaces rub together. Moving objects slow down because friction acts in a direction opposite to the motion of the object. Constant velocity and friction- an object will not change it’s velocity until the forces are no longer balanced. Friction is an example of how forces can become unbalanced.

2 nd Law of Motion (continued) Kicking a ball Book Slinky Dog Goo

More about Acceleration… Acceleration is the rate of change in velocity(motion). The formula for finding acceleration is: acceleration= final velocity – initial velocity time Example: A racing roller skater who changes velocity from 5m/sec. North to 15 m/sec. North in 5 seconds. What is the acceleration?

It takes force for something to accelerate! Movie not produced or created by teacher…no copyright intended.

How do you know how much force is necessary to get an object to accelerate? The strength of the force equals the mass of the object multiplied by the acceleration of the object. »Mass (grams)- amount of matter in an object (balances) »Acceleration (m/s 2) - a change in velocity (motion) Algebraically it is: Force = mass x acceleration or F = ma

Practice Problems A baseball player hits a 0.1 kg baseball to accelerate it at a rate of 4000 meters per second squared. What is the force of the player’s hit? A soccer goalie kicks a ball with a force of 900 newtons. The ball is 0.5 kg. At what rate will the ball accelerate? (remember: 1 N = 1kg m/s 2 ) A stalled car is 1000 kg. It is pushed forward with a force of 2000 N. At what rate does the car accelerate?

Newton’s 3 rd Law of Motion! Whenever an object exerts a force onto a second object, the second object exerts an equal force back onto the first object. “For every action there is an equal and opposite reaction!” In other words: you can’t touch something without it touching you back. For example: walking, rowing a boat, kicking a ball, arm wrestling, etc…

Motion Has Momentum! Momentum (symbolized by the letter P) is a measure of moving objects and is the product of an object’s mass(m) and velocity(v) or : P = mv

Law of Conservation of Momentum: No momentum is lost when two objects collide! Newton’s cradle!! When an end ball is pulled up and let go, it swings down as a pendulum and hits the next ball. The energy and momentum from that ball is transmitted through the three balls at rest to the ball on the other end. That ball is propelled forward at the same speed as the first ball had due to the force of the first collision. What about two balls?

Newton’s Universal Law of Gravitation! Gravitational attraction- the force of attraction that causes every object in the universe to attract every other object. Newton developed the Universal Law of Gravitation: The amount of gravitational force between two objects depends on two things: 1)The mass of the object. 2)The distance between them.

Direct/Positive Relationship vs. Indirect/Negative Relationship Two types of relationships!

Direct or Positive relationship is when you have two variables and whatever happens to one variable is the same as what happens to the other variable. The same thing happens to both variables! Indirect or Negative relationship is when you have two variables and whatever happens to one variable is the opposite of what happens to the other.

What is the relationship between Mass and Gravity? Mass and Gravity have a Direct/positive relationship! As Mass increases, Gravity As Mass decreases, Gravity increases. decreases.

What is the relationship between Distance and Gravity? Distance and Gravity have an Indirect/negative relationship! As Distance increases, Gravity As Distance decreases, Gravity increases. decreases.

Force needs energy! Two types of energy: Potential energy- stored energy determined by its shape and/or position. Kinetic energy- energy due to its motion.

Law of conservation of energy Energy cannot be created nor destroyed! It is just absorbed by matter and used and released back into the atomosphere to be absorbed and used again and again!!!!

The End! I hope you enjoyed!!!!