Forces

class: center, middle

.title[Balanced and Unbalanced Force Particle Models]

.subtitle[A Casual *Model* for Particles 🚗🚗🚗]

.author[👨🏻‍🏫 Nathan Porter]

.institution[🏫 Maple Hill High School]
 
.coauthor[]
.institution[]

.date[📅 2022-2023]
 
 
 
.center[]

---
class: middle

#Which objects move with constant speed?

#What do you notice about the conditions where the objects move at a constant speed?

---
class:center, middle

---
class:center, middle

---
class:center, middle

---
class:center, middle

---
class:center, middle

---
class:center, middle

---

#Bowling Ball Physics

###We are going to try and recreate constant velocity motion with objects moving over smooth, hard, level surfaces.

- First with a bowling ball,
--

- then with with fan carts

###Bowling Ball Situations - Using a mallet and a bowling ball:

####Each time we use the mallet, let it bounce. (Don’t use the mallet like a bulldozer.)

- Start with a stationary bowling ball. Then, speed up the bowling ball from rest.
- Have someone roll a bowling ball. Then, bring it to a stop.
- Have someone roll a bowling ball. Then, keep it moving at a constant velocity.
- Have someone roll a bowling ball. With one tap, have the bowling ball make a 90 degree turn.

### .tom[Your goal: summarize the relation between taps and motion in as few statments as possible]

---

#Lab Safety:

1. No High Mallets 
2. Be aware of your surroundings 
3. No excessive rolls 
4. No smashing into walls, mats, classmates, etc.

---

class:center, midde

#How do taps relate to the motion of the bowling ball?

---

class:center, middle

#Does our rule relating motion and taps work for the bowling ball tapping the mallet? Or in other words does the bowling ball tap the mallet?

---
class: center, middle

#Rolling Chair Demo

---
class:center, middle

#What would happen as we make the taps more "constant"?

---
class:center, middle

#Describe the "taps" that affect the motion of the fan cart

---

#Dueling Fan Carts

1. Off vs. off
--

2. Off vs. off, then give the carts a push
--

3. On vs. vs. off
--

4. On vs. on
--

5. On vs. on, then give a cart a push

---
<!-- 
#Solving Force Problems

1. Draw Free Body Diagram
--

2. Determine if Balanced/Unbalanced
--

2. Determine (+) and (-) directions
--

2. Draw vector addition diagram
--

2. Split forces into components (if necessary)
--

3. Write Force equation in perpendicular directions (usually x and y directions, but varies if ramp at angle)
--

4. Solve for unknowns

---
class:center, middle
<img src="https://cnx.org/resources/f11d3f67fb6f740f12f29693a0a5a8a41f2374a7" width = "800px"/>

---
class:center, middle

---
<img src="G:\My Drive\GitHub\mrporterphysics.github.io\Presentations\Forces\figures\tension.PNG" width = "300px"/>

Sum Forces in x-direction:

`$$\Sigma F_x = -T_{1x} + T_{2x} = 0$$`

`$$T_{1x} = T_{2x}$$`

$$T_1\cos(30^\circ) = T_2\cos(45^\circ)$$

And sum in y-direction...

`$$\Sigma F_y = T_{1y}+T_{2y}+-F_g = 0$$`

`$$T_{1y}+T_{2y}= mg$$`

`$$T_1\sin(30^\circ)+ T_2\sin(45^\circ) = mg$$`

---

class:center, middle

For inclined planes, we rotate the coordinate axis and refer to the directions as the parallel direction and perpendicular direction.
Both of these are references to the ramp. Next we split up gravity into its parallel and perpendicular components.

---

#Memorize These!

###(Or know how to derive them!)

#`$$F_{g\parallel} = mg\sin(\theta)$$`

#`$$F_{g\perp} = mg\cos(\theta)$$` -->