Forms of Energy

QOD

1. What are the 5 types of energy?2. Potential Energy and Kinetic Energy

are examples of what type of energy?

QOD- Answers

1. What are the 5 types of energy?1. Mechanical (moving energy)2. Chemical3. Electromagnetic4. Thermal (heat)5. Nuclear

2. Potential Energy and Kinetic Energy are examples of what type of energy?

MECHANICAL ENERGY!

Forms of Energy

Mechanical – involves movement or the potential for movement (2 forms)

1. Potential Energy – stored energy (PE)-Not moving energy, but potential to move-“Gravity” is the force acting on an object will

move if allowed to-Impacted by Mass, Gravity and “Height”

2. Kinetic Energy - Energy in motion (KE) Impacted by - Mass and Velocity

How Energy is Related to Work…

How Energy is Related to Work…

Once the bow is released, what kind of energy is found in the arrow?

Equations

Potential Energy = (mass)(gravity)(height)PE = m x g x h

Units of measurement Mass = kg Gravity = m/s2

Height = meters

Units for Potential Energy = Kgm2/s2 = Newton meter or a JOULE (J)

Kinetic Energy = (1/2)(mass)(velocity2) KE= 1/2 mv2

Units for Kinetic Energy = Newton Meters or JOULES(J)

Examples of PE and KE

Roller Coasters Ski Mountains

Make mucho $ on PE & KE (you pay for PE-lift ticket) Rain Forest Zip-Lines

Water Slides Pendulums (physicsplace.com)

Energy is Conserved

“Energy cannot be created or destroyed.”

Conservation of Energy

PE + KE = Total Mechanical Energy Energy can transfer from PE to KE

Like a see saw battle (as one gains the other loses) Ex: If total energy = 100% at all times…and there is 25% PE then there would be ___ KE

You can never gain more energy than you started with…

you can’t gain more height without added force!

Converting Energy PE --> KE

In Theory… 100% PE converts to 100% KE

So PE = KE

mgh = 1/2 mv2

Can you predict velocity based on height of an object? (hint: solve for velocity)

Velocity = square root of (2*g*h)

Roller Coaster Physics

1. Name two of the forces that affect the motion of the car while it moves on the roller coaster.

2. Describe how the potential and kinetic energy of the car change as the car rolls downhill.

3. Can the car reach point X on the track? Why or why not?

Pendulum Calculation

1. If h = 20 cm and the purple ball has a mass of 10 kg, then what is the PE of this pendulum?

2. What would be the pendulum’s velocity at the spot where the pendulum is at it’s lowest point?