# Do Now Monday, November 18, 2013 - PowerPoint PPT Presentation

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Do Now Monday, November 18, 2013. Periods 1&2 get ready for your Unit #5 Exam. Afterwards, you will complete your guided notes using the ppt online. 3.5 minutes. Do Now Check. Do Now Monday, November 18, 2013.

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Do Now Monday, November 18, 2013

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#### Presentation Transcript

Do Now

Monday, November 18, 2013

Periods 1&2 get ready for your Unit #5 Exam. Afterwards, you will complete your guided notes using the ppt online.

3.5 minutes

Do Now Check

Do Now

Monday, November 18, 2013

What is Newton’s 3rd Law of Motion? Provide a real-world example of Newton’s 3rd Law.

3.5 minutes

Do Now Check

• By the end of the day today, IWBAT…

• Compare and contrast kinetic and potential energy

• Calculate kinetic and potential energy

Why it matters in LIFE: Energy is what allows us to move!

Why it matters in THIS CLASS:

This is a HUGE topic that is central to your understanding of everything we will be doing this semester.

### Unit 6: Work, Power, and Energy

Unit Cover Sheets

Trackers

### What is energy?

• ENERGY is the ability to make things move or change

• Measured in Joules (J)

### Forms of energy

• Energy can exist in many different forms and changes from one form to another

### Kinetic and Potential Energy

• For this unit, we are going to be focusing on the energy of movement

• Two main types: Kinetic and Potential

### Kinetic Energy

• KINETIC ENERGY is the energy of motion

• Depends on mass and velocity

### Kinetic Energy

Which has a higher maximum kinetic energy, my first car or the camaro? Why?

The camaro has more KE because it has a higher velocity.

### Kinetic Energy

Which would hurt more, getting hit by a 15 foot wave or a 2 foot wave? Why?

The bigger wave would hurt more because even though they travel at the same speed, the bigger wave has more mass.

### Kinetic Energy

• Formula:

KE = ½mv2

mass (in kg)

velocity (in m/s)

### Kinetic Energy

• The bird has a mass of 2 kg. It is flying at a speed of 5 m/s. Find its kinetic energy.

KE = ?

m = 2 kg

v = 5 m/s

KE = ½mv2

KE = ½(2 kg)(5 m/s)2

= 25 J

### Potential Energy

• An object with POTENTIAL ENERGY has the ability (or potential) to move or change

• Sometimes called “energy of position” or “stored energy”

• There are 3 types of potential energy:

• Gravitational Potential Energy

• Elastic Potential Energy

• Chemical Potential Energy

### Gravitational Potential Energy

• Potential Energy due to an object’s position

• Formula:

PE = mgh

height (in meters)

mass (in kg)

acceleration of gravity (9.8 m/s2)

### Gravitational Potential Energy

• The person has more potential energy at the top of the stairs than at the bottom.

### Gravitational Potential Energy

Where does the egg have more potential energy? Why?

### Gravitational Potential Energy

• If your egg drop device has a mass of 2 kg, how much potential energy does it hold at a height of 10 meters?

PE = ?

m = 2 kg

g = 9.8 m/s2

h = 10 m

PE = mgh

PE = (2 kg)(9.8 m/s2)(10 m) = 196 J

### Elastic Potential Energy

• Potential energy due compression or expansion of an elastic object

### Chemical Potential Energy

• Potential energy stored within the chemical bonds of an object

### Kinetic or Potential?

Every pair will receive a whiteboard and a marker.

I will put a picture up on the board.

You will have 30 sec to decide whether the picture represents kinetic or potential energy.

Do not put your board up until I say.

Joules (J)

PE= mgh

Potential

Kinetic

Chemical

Gravitational

KE = ½ mv2

Elastic

mass

velocity

mass

position

### Practice Problems

• 10 min to complete the practice problems

• Work together

• Show all of your work!!

• Raise your hand if you have a question

### Exit Ticket

• Complete the questions silently and independently

• Hand it to me on your way out when the bell rings

• Remember – I want to see your BEST work!