U2C2A3 RSp 162

Key Question: What happens to the energy in applied, friction and drag interactions?

We Thinkpage 162

#’s 1-2

Explore Your Ideas

page 163

Explore Your Ideas

Part A: Energy Diagrams for AppliedApplied Interactions

Step 1

page 163

Part A: #1

stored chemical motion

AppliedApplied

You have You have 6 minutes6 minutes to to complete #s 2 – 4 on p 164 complete #s 2 – 4 on p 164

Read Step 2 #s 2-4

on p 164

Part A: #2

AppliedApplied

Part A: #3

AppliedApplied

Part A: #4AppliedApplied

Part B: Energy Diagrams for FrictionFriction Interactions

Step 1: Friction video

5. In both cases, what was the evidence that a friction interaction had occurred?

5. In both cases, what was the evidenceevidence that a friction interaction had occurred?

Rubbing hands: There was a change in….

Wooden block rubbed along table: There was a change in….

Now it’s your turn!

Step 2: Rub the palms of your hands together.

6. What is the evidence that a friction interaction is occurring?

Step 3: Gently shove one of your books so that it moves across your desk. There is a friction interaction between the book and the desktop.

7. What do you observe?

You have You have 6 minutes6 minutes to to complete #s 8 - 11complete #s 8 - 11

Read p.p. 165-166 to answer #’s 8-11 (Do Not move on to Part C.)

Part B: #8

Part B: #9

Part B: #10

Part B: #11

The source The source decreases in decreases in motion energy.motion energy.

The receiverThe receiverss increase in increase in thermal energy.thermal energy.

s

FrictionFriction

motionmotion thermalthermal

Part B: #11

Part C: Energy Diagrams for DragDrag Interactions

Step 1: video - drag in air (Watch, then complete #’s 12-14)

Part C:#12DragDrag

car/parachutemechanical

energyair

decreases in motion energy

increases in motion energy

Part C:#13DragDrag

boatmechanical

energywater

decreases in motion energy

increases in motion energy

Part C: Energy Diagrams for DragDrag Interactions

Step 3: Think about a rider on a bicycle. Bicycle riders experience a lot of drag!

Part C:#14DragDrag

bike ridermechanical

energy air

decreases in motion energy

increases in motion energy

You have You have 5 minutes5 minutes to to complete complete Make Sense Make Sense of Your Ideasof Your Ideas #s 1 - 3 #s 1 - 3

Make Sense of Your IdeasQuestion 1

1. In general, what evidence shows that an applied interaction has occurred?

The receiver

increases

in motion energy.

Make Sense of Your Ideas Question 2

2. In general, what evidence shows that an friction interaction has occurred?

The receivers

increase

in thermal energy.

Make Sense of Your Ideas Question 3

3. In general, what evidence shows that an drag interaction has occurred?

The receiver

increases

in motion energy.

Question 1 - Applied Interaction

motion

The source The source decreases in decreases in energy.energy.

The receiver The receiver increases in increases in motion motion energy.energy.

AppliedApplied

In an applied mechanical interaction, the energy from the receiver often gets transformed into motion energy of the source.

Question 2 - Friction Interaction

thermal

Receivers

The source The source decreases in decreases in motion motion energy.energy.

The receiverThe receiverss increase in increase in thermal thermal energy.energy.

motion

FrictionFriction

Question 2

•In a friction interaction, the energy source (motion energy) gets transformed into thermal energy of the receivers (both surfaces rubbing against each other).

Question 3 - Drag Interaction

Re-write your answer to #3.Re-write your answer to #3.

DragDrag

Question 3Drag Interaction

motion

The source The source decreases in decreases in motion motion energy.energy.

The receiver The receiver increases in increases in motion motion energy.energy.

motion

Question 3

•In a drag interaction, the energy of the source (motion energy) gets transformed into motion energy of the receiver (the gas or liquid the source is in).