What are two types of Mechanical Energy?

Mechanical Energy is either kinetic or potential energy

List situations/examples of each type

AIM:

What are the two types of Mechanical Energy?

KINETIC ENERGY, POTENTIAL ENERGY

Mechanical Energy

AIM:

How can you make a stationary ball move faster, or slower?

What does that have to do with energy?

MiniLAB: Dropping Tennis Balls •Drop a tennis ball from a height of 1m and .5m•Record its bounce height•Graph your results•What is the relationship between height and bounce?•Can you interpolate for a release height for .75m. Can you extrapolate for a release height of 2m.•Which ball had the most energy a) or b)?

Mechanical Energy:

Energy of movement

TWO TYPES:

Kinetic or Potential

Kinetic Energy:

is defined as the energy of motion

if an object is moving it has kinetic energy

also used to describe the energy of the also used to describe the energy of the movement of moleculesmovement of molecules

The Amount of Kinetic Energy:

Depend on two things:

1) the MASS of the object2) the velocity the object is moving

What would hurt more:

A Ping Pong ball falling on your head

OR, a Basket Ball falling on your head?

Why?

Which has more energy? Why?

What would hurt more:

A base ball I toss at you’re stomach?

OR, a baseball I “whip” at your stomach?

Why?

Which has more energy? Why?

There is actually a formula which mathematically expresses this relationship:

(mass)(velocity2)= K.E.

The amount of energy depends on the object’s MASS and how fast the object is traveling!

Which freight train has more energy?

A 10 ton train or a 20 ton train?

(mass)(velocity2)= K.E.

WHY?

Which freight train has more energy?

A 10 ton train travelling at 20 mph, or a ten ton train travelling at 50 mph?

(mass)(velocity2)= K.E.

How could you tell?

Examine OH #49

Which vehicles have more KE?

Why?

Acrobat Document

WHICH VEHICLE HAS MORE KE? WHY?

1000 Kg.

1000 Kg.

180 Kg.

Potential Energy:

is defined as stored energy …

Or as the energy of position

TWO TYPES:

Gravitational …and…Elastic

Potential Energy:

#1: Gravitational potential energy due to the position of the object with respect to gravity

…the higher the object is above the ground, the more potential energy it has

… AND …

#2 Elastic Potential Energy-

best describe by example: a stretched rubber band, or an archer’s bow possesses Elastic Potential Energy

Which possesses more energy?

A book on a table has stored potential energy.

When the book falls that energy is released.

Its potential energy converts to Kinetic Energy

Mechanical Energy

KINETIC ENERGY POTENTIAL ENERGY

Mass

Velocity

Gravitational

Elastic

Potential Energy:

Which has more potential energy?

A marble in position #1 or #2?

How can you tell?

Question:

Does an object having greater mass have greater potential energy?

How could you test this?How could you design such an experiment?

Worksheet Concepts 3-1Worksheet Handout Potential vs. KineticConcepts W/S #11

Homework:

INTERNET QUESTIONS

FINISH WORKSHEETS

Write a Paragraph summarizing the AIM

Performance Assessment:

Performance Assessment: The Nature of Energy Assess students' understanding of the nature of energy by having them draw a sketch or diagram of playground equipment and label positions where a child would have potential energy and kinetic energy.