Forms of Energy and Energy Transformations Energy Basics
Forms of Energy and Energy Transformations
Energy Basics • • Energy is the ability to do work All forms of energy can be in either of two states: Potential (PE) and Kinetic (KE) When PE KE – Potential – stored • Dependent on mass and position – Larger mass = greater PE – Higher up = greater PE – Kinetic – moving • Dependent on mass and velocity – Larger mass = greater KE – Greater velocity = greater KE http: //www. brainpop. com/games/coastercreator/
Atomic / Nuclear Energy https: //www. brainpop. com/science/e nergy/nuclearenergy/ • Potential energy in an atom – Can be split apart (fission) – Can be put or fused together (fusion) Click to add text – Mainly used for generating electricity but also Click to add text used in medicine (diagnosis and treatment) and industry and radiometric dating
Chemical Energy • Potential energy that is stored in the bonds of atoms and molecules; when the bonds are broken the energy is released • Sources include: – Burning / Combustion – Food – Fuels/gasoline – Batteries – Photosynthesis
Heat (Thermal) • Kinetic energy of particles – More particles = greater heat – Faster moving = greater heat • Transferred 3 ways Conduction • Touching • Aluminum bar heats up and transfers energy to the cold water Convection • Currents in fluids • Hot water rises, cools then sinks where it is heated again Radiation • Through space • Energy from the Sun reaches Earth through radiation
Mechanical (motion and machines) • Kinetic energy in a moving object that is doing work • Simple machines are used to provide extra force to move an object (make the work easier)
Mechanical Math Some “motion” formulas to consider: Speed = distance / time Velocity = speed in a certain direction Acceleration = ∆Velocity / time Some “machine” formulas to consider: Work = force x distance Power = Work / time MA = output / input ME = output * 100% / input
Newton's Three Laws of Motion First: An object at rest stays at rest and an object in motion stays in motion unless acted upon by an outside force. Second The force an object exerts is equal to its mass times its acceleration. Third For every action, there is an equal and opposite reaction.
An object at rest stays at rest and an object in motion stays in motion unless acted upon by an outside force. • The object sits there 'til something moves it and moves 'til something stops it • Law of inertia – Inertia is the ability of an object to resist change
FORCES can. . . • Make objects move (speed up/slow down) • Make objects stop • Make objects change direction • Forces include: – Gravity – Magnetic – Electrical – Resistance ~ FRICTION – Tension (string, rope, cable) climbing a mountain – Spring – Normal (1 is stable) pushing on a wall
Friction OPPOSES motion • Rolling • Object rolls over surface, wheels • Sliding • Two surfaces slide past each other, sliding into home plate • Fluid • Air resistance or moving though a liquid, swimming, throwing a ball
An object at rest stays at rest and an object in motion stays in motion unless acted upon by an outside force. • Why we wear seatbelts in a car and why airbags deploy
An object at rest stays at rest and an object in motion stays in motion unless acted upon by an outside force. everyday examples: • A hockey puck sliding on ice until it hits the boards or a hockey stick • A soccer ball sitting on the ground until a player kicks it • Zion Williamson's foot going through his sneaker when his sneaker stopped moving. . . ouch
The force an object exerts is equal to its mass times its acceleration. It is easier to push (force) an empty grocery cart than a larger cart because the empty cart has less mass
Second Law Calculations: The diagram represents a cart with a mass of 10 kilograms (kg) being pulled to the right with a force of 20 newtons (N). Using the equation above, calculate the acceleration of the cart in meters per second squared (m/s 2).  _______ m/s 2
A wagon with a mass of 50. 0 kg accelerates 8. 0 m/s 2 when the parent pulls it. What is the amount of the force required? A force? How much force would the parent need to use to pull the wagon with 200. 0 kg, while keeping acceleration at 8. 0 m/s 2?
For every action, there is an equal and opposite reaction.
Equal and Opposite
Electricity and Magnetism • Electricity • Flow of electrons • Static or current • Magnetism – Static • Lightning • Rubbing foot on rug • Balloon on head/wall – Current • Two kinds: – Series – 1 path – Parallel – more than 1 path • Need: resistor (bulb), wire, battery • Also can use: switches – Closed = on – Open = off – 2 poles (North and South) – Poles are strongest – Even if cut in pieces each piec would have N and S poles – Opposites attract and likes repel
Light • Radiant energy moving in transverse waves and packets (photons) • Visible light makes up part of the electromagnetic spectrum