Chapter+1

flat =__Section 1: Reaction Time__=

**What do you see?**
I see a car accident (the two cars are orange and yellow) and a incoming car (blue) trying to stop so they don't hit the two other cars.

What factors affect the time you need to react to an emergency situation while driving?
Condition of the road, when the person saw the event, coordination, and age affect your reaction time.

**Investigate**
6 in. between gas and brake It took me 10 seconds to switch my feet from the gas to the brake 9 times.

when i switched my foot from the gas to the brake after hearing the sound it took me about a second to react.
Method A: Stopwatch

It took me .22/.12/.24 seconds to react to my partner stopping his stop watch
 * A.**

Comparing Methods :

1.

a) There are many factors why the times weren't the same such as how quickly you reacted to a falling object or how quickly you reacted to your partner stopping the stop watch.

b) I think the Stop watch method is the most affective because your partner could mess up the ruler method by accidently missing or dropping the ruler.

2.

a) My .12 sec was the fastest reaction time during the stop watch and the .35 sec my partner had was the slowest reaction time.

b) Age definitely affects a person's reaction time considering that an 80 year old person could barely run at the same speed as a 25 year old person.

Method C(1): Ruler

Distances: ruler traveled before caught: 21cm (4 times) and 27 cm 21cm= .21 seconds 27cm= .247 seconds
 * A.**

Reaction time without distractions:
 * B.**

1:red(74cm) 2:red(27cm) 3:green 4:red(55cm) 5:red(25cm)

Now while distracted:

1:red(24cm) 2:red(44cm) 3:red(50cm) 4:red(55cm) 5:green

Method B (1) questions:

**A.**
The reaction time while distracted is better even though it took a couple of tries to get five right in a row.

**B**//.//
//This applies by because in a real situation you might need to react quickly and this tells us how quickly you respond.//

Method B (2) questions:

**A.**
//My reaction time not distracted is worse compared to my reaction time while distracted.//

**B.**
//-Calling someone// //-Texting// //-Changing radio station// //-Talking// //-Singing// //-Dazing off// //-Scratching// //-Playing araound// //-Breaking up an argument in the backseat// //-Writing//

**PHYSICS TALK**:
questions:

1) Distractions slow down your reaction time because your mind is in one place while you aren't paying attention to the main objective you are trying to do.

2) Driving under the influence is illegal because it doesn't just slow down your reaction time but it also makes you think differently and is the cause for most accident deaths.

3) Talking, looking, and changing the radio can affect your reaction time.

Physics to go:
1) Random stranger in school lobby: .23 seconds= 25 cm Old lady: .27 sec= 30cm My friend: .19 sec= 19cm

2) The people in class knew what was coming considering that they had done it and witnessed it before while the others didn't.

4) I think it is the same considering that anything could happen at any time such as someones brakes broken in a school zone and their car is unstoppable. An example of a race car driver is if they have to react to a turn every .5 of a lap and if they don't react in time then they could flip over and then their life is at risk.

5) It increases the persons reaction time.

6) That is the difference between life and death

7) That is because teenager drivers are more prone top accidents considering that they are new on the streets.

8) If you know your own reaction time then you know what your limits are and how you can change others lives, jobs, etc...

=__**Section 2: Driving the Roads**__=

I see a cat, a person measuring another walking, a girl walking behind a guy jokingly, and they all are in a school.
 * What do you see?**

Well, one could have made a mistake but there could have been more skid marks.
 * What Do You Think?**
 * If one student measures the skid marks at 3 m and the other at 10 m, then has one of them made a mistake?**

No because they are practically the same numbers.
 * If the measurments were 3 m and 3.01 m then was there a mistake?**

**Investigate:**

 * Group 2= Me and Cassie ( I am on the Bottom)**
 * Actual distance= 1315.5** **cm**
 * 7)**
 * a. they all are relatively the same except for the 924 and the 1239.**
 * b. Some peoples strides may be bigger than othersand there is always some kind of error in this type of math.**
 * c. I guess the only way to actually get all around the same answer is to measure each others exact strides and make everyone take the same length of a step in order to get the same distance.**
 * d. No group would have gotten the same number.**
 * e.No you can't because no system can be so exact that everyone gets the same answer.**


 * What do you think?**
 * - no but there had to of been an error.**
 * - no because you can never get the same measurement twice**

**Physics to Go**
__**1.**__
 * A) 49.9 m - 50.1 m**
 * B) 49.99 m - 50.01 m**
 * C) 49.999 m - 50.001 m**


 * 2.**
 * Speed= distance / time**


 * speed = 50 m / 25 sec= 2m/s**


 * 2m/s= .02 cm / time**


 * 2m/s x t = .02m**


 * t = .01 sec**


 * 3.**


 * Speed= distance / time**


 * speed= 1500 m / 900 sec= 1.67 m/s**


 * 1.67m/s= .6 m / time**


 * 1.67m/s x t = .6 m**


 * t = .36 sec**


 * 4. The tanker usually can't hold that much oil and the uncertainty is that each barrel can easily be lost.**
 * 5. Fruit snacks, milk, kool-aid, Doritos, and cookies; Their labels are accurate because the government takes the label very serious because these foods can make people sick.**
 * 6.**
 * a) No this is not reasonable because some people take more than others so therefore it can't support 12 people**
 * b) It matters what kind of car it is.**
 * 7. Yes it is because 1 m is 1 m and that can't change.**
 * 8.**
 * a) you should go 60 mph**
 * b) The passenger could count the amount of time it takes on his watch.**


 * 15.5 strides**
 * 1 stride= 32.8 in**
 * 508.4in. in length**
 * real length= 507in.**


 * 30 minutes to get ready in the morning - Agree**
 * Walking to school- Disagree**

=**__Section 3:Average Speed__**=

Bumper to bumper collision and the blue car was stopping and was distracted by a bunny and the scenery. There is also a mile marker is directly across from the bunny**.**
 * What Do You See?**

- A standard distance to be behind someone is 3 seconds behind someone. - You can count three Mississippi's to see how far away you are.
 * What do you think?**


 * 1)**
 * a. X....X....X**
 * 2)**
 * a. X......X......X**
 * b. The image going 45 mph covered more distance than the 30 mph one**
 * c. X........X........X**


 * 3)**
 * a. In diagram A it is the slowest and in diagram C it is the fastest.**
 * b. You know they are constant because they the same length in between cars.**


 * 4)**
 * a.**
 * b.**
 * c.**
 * d.**


 * e. The graphs are similar because they all have slopes that are affected by the person moving. The direction and speed affected the graph because if you til or walk not in a straight line then it catches something else on the graph and if you walk slow then the graph gradually goes up.**


 * 5)**
 * a.**


 * b. It was pretty accurate.**


 * 7)**
 * a. 2 ft**
 * b. 1.4 sec**
 * c. 1.43 ft/sec**


 * 8)**
 * a. 30 ft**
 * b. 90 ft**
 * c. 25 ft/75 ft**
 * d. 35 ft/105 ft**
 * e. 30 ft**

**Physics to Go**

 * 1)**
 * a. The car is going at a constant speed**
 * b. The car is going at a constant then it speeds up and then goes back to a constant speed.**


 * 2)**
 * a. X..X....X......X.......X.........X.........X.........X.........X**
 * b.X......X......X......X......X...X..X.X**


 * 3) 350 ft/sec x 20 sec = 7,000 ft/sec**


 * 4)**
 * a.215 / 4.5 = 47.77mph**
 * b. It isn't possible because it is at it's average already**


 * 5) 60mph**


 * 6) Because graph d accelerates while the other graphs make a sudden stop with out time moving which is impossible.**


 * 7)**
 * a. 12.5 meters because your reaction time is .5 seconds**
 * b. 1.6 times slower at 55 mph then to 30 mph**
 * c. 39.3 meters during your reaction time.**


 * 8)**
 * a. They can test how long it takes a car to stop.**
 * b. Yes because it's about how far the car in front of you travels in the 3 second**


 * 9)**
 * a. 33 ft**
 * b. It's about the same as the length of the classroom**


 * 10)**
 * a. It goes 44 ft because it is .5 secs and it goes 88 ft in 1 sec.**
 * b. It depends how fast that 15 ft car is going.**
 * c. 3 car lengths and the distance traveled in .5 sec is 22 ft per sec.**
 * d. 9 car lengths at 90mph then it travels 66 ft in .5 sec**
 * e. 30mph= 44 ft, 60mph= 88 ft, 90mph= 132 ft**

**Active Physics**

 * 1.**


 * 2.**


 * 3.**
 * a. 35 mph**
 * b1. 18.75 mph**
 * b2. My estimate wasn't far off but I still could've guessed a little bit better.**

**What do you think now?**

 * -3 feet is a safe distance**
 * -by counting three seconds when behind a car**

=**__Section 4: Distance, Velocity, and Acceleration__**=

- Speeding through red light - person running - town landscape - yellow car seems to be taking its time
 * What do you see?**

A bus takes more time to hit 30mph because it weighs more and a car is lighter and also a car is lower to the ground so therefore it has enough leverage to pass the bus very easily. They are bot similar because they both have to accelerate at the same time.
 * What do you think?**



Investigate

 * 1a. It will continually accelerate**


 * 1c.**


 * 2a. [[image:Screen_shot_2011-10-12_at_12.00.23_PM.png width="560" height="350"]]**


 * 2b. My prediction was the same as the actual graph**


 * 2c. slopes= 5/4 and 3/4**


 * 2d. The car accelerates and moves away from the sensor so therefore the keeps gaining speed.**


 * 2e.**


 * 3b.The graph starts at zero because the amount of time it takes to get started isn't important and only the slope is important.**


 * 3c. As time increases the slope stays the same because it covers the same amount of area because gravity pulls the same amount of force at any time.**


 * 3d..7m/s-.35m/s= .35m/s / .6s= .583 m**


 * 4a.** **It will be going down because it is starting farther away and will go down then curve until it's straight.**
 * 4b. I think that it will start negative and then it will go up to zero**


 * 5a**1**.**

2.




 * 5c. The car goes toward the car really fast but also starts to slow down until it has to back to the bottom of the ramp.**


 * 5d. The slope stays the same because gravity pushes on the car at a constant force.**


 * 6a. The car gets pushed away**




 * 6b. The car accelerates but then starts to slow down when it gets closer to the top**


 * 7a1.**
 * 7a2.**


 * 8. graph 1:** **The motion sensor would be placed at the top and the cart would be pushed down.**
 * 2: The motion sensor would be at the bottom and the cart pushed down**
 * 3: The The motion sensor at the top but it is v-t not d-t**
 * 4: The motion sensor at the bottom and car getting pushed up**


 * 9.a. The graph is just showing acceleration.**


 * 12a. velocity(15)/time(.9)= 16.66**
 * c. It was pretty close because we calculated the average acceleration in order to help us.**

**Physics Talk**

 * - Galileo**
 * - Acceleration= change in velocity/ change in time**
 * - Accuracy and Precision- Water Clock**
 * - Vectors- Magnitude and direction (speed vs velocity)**
 * - Negative and Positive Acceleration**
 * - Ways to change velocity- Speed Up, Slow Down, Change Direction**
 * - 3 ways to describe acceleration: 1. Strobe photos 2. Equation 3. Graphing**

**Physics To Go**

 * 1. No because then the car isn't in motion.**
 * 2. No because if the object has no velocity then it has no acceleration.**
 * 3. No because their are other factors that contribute to their velocity such as weight or horsepower.**
 * 4. No because they might have gone faster than the other in the beginning.**
 * 5. No because the velocity can turn negative if a change of direction occurs.**
 * 6. No because to me they are pretty much the same because they are both represented as mph.**
 * 7.**
 * a. 60/5=12x2= 48mph**
 * b. .066666 miles**
 * 8. a. 75=0+a(9)=8.3333**
 * b. .5(0+75)(9)=337.5=Vavg(9)=37.5**
 * c. 337.5**
 * 9.?**
 * 10.**
 * a. 14m/s**
 * b. 1.2m/s**
 * c. It will remain constant**
 * 11.**
 * a. A**
 * b. C**
 * c. D**
 * d. B**
 * e. F**
 * f. E**
 * 12.**
 * a. D**
 * b. B**
 * c. G**
 * d. F**
 * e. 510 m**
 * f. 0 m**
 * 14. 35 mph**

=__**Section 5: Negative Acceleration- Braking Your Automobile**__=

**What do you see?**
- car tries to break suddenly - Forest scene - Moose suddenly appeared - Person seems startled

**What do you Think?**
You must factor in the conditions of the road, the surroundings, and the speed of the car and the animal.


 * Investigate:**



Major factors are initial velocity and final velocity, speed, and distance. The most important is your distance. There isn't only one factor though.
 * What do you think now?**


 * Essential Questions**


 * 1.** The faster you go, the longer it takes for you to stop.
 * 2.** The velocity is squared
 * 3.** This can safe us from many accidents with animals or other objects

1. 2. A is safer because it has a slower acceleration than the other one. 3. A=22.5 4. 39 m 5. ? 6. ? 7. ?
 * Physics to go:**

=__**Section 6: Intersections with a Yellow Light**__=

- Investigate factors of stop and go zones at intersection. - Investigate factors that result in Overlap Zone at intersection
 * Learning Outcomes:**

- Red light appeared but one car was having trouble stopping - Police officer notices car who is exceeding the line - people on sidewalks seem angry or furious at car. -Every one would be either cautious and slow down or they might speed up and know that they could make it through the light. -A fault in the traffic light can cause multiple accidents
 * What do you See?**
 * What do you Think?**

3a. Yes the automobile can make it because it is going at the same speed as automobile B. And if automobile B can make it then A can also make it. 3b. Yes because A is in the go zone and B is before A. 3c. Yes because A is in the go zone. 3d. No automobile c is not in the go zone and if they continue the light may become red but they are on the border of making it. 4a. Yes car A is in the stop zone because it is far enough 4b. No, automobile F is probably not in the stop zone. If he decides to stop then he will probably drift into the middle intersection. 4c. Stop Zone= Car C and E Go Zone= Cars: A B D F 5 b&c. 6a. 53 meters 6b. 63 meters 6c. of course 6d. +light= more time -light= less time
 * Investigate:**

8a. I wasn't surprised with the affects of the variables when they are changed 8b. No my predictions were not correct I did not think that some of the variables would have no effect on the go zone. 8c. velocity of (vehicle x time of light) - width of intersection= Go Zone 8d. It appears because in order for the car to make out before the light turns red then it has to be calculated like that. 8e. Because they don't affect how fast the car can make it through the intersection. 9a. (Velocity of car x reaction time) + [Velocity^2 / (2 x Negative acceleration)] 9b. Width isn't included because the Stop Zone means you are trying to stop and you are no going through the intersection. 9c. They are involved because they decide how far the stopping distance goes. The other variables aren't include because they involve going past the intersection. 1a. If I was in Car A=not go, Car B=go, Car C=go, Car D=not go. 2a. E=no, F=no, G=yes, H=yes 3a. J=stop, K=go, M=undefined, L=stop 4a. They are all different because the cars have different stop or go zones. 4b. I would most likely go if I was in the in between zone but that is probably not the safest decision. But I would make this decision because a car is not normally going to be flying out of the green light so you are safe. 4c. If I was in the in between zone I would not go because it would not be safe and you only want to go if you are in the go zone. 4d. Intersection 2 is an overlap zone and intersection 3 is a dilemma zone. 5a. 6a. 6b. The width of the north south intersection is 25 m and the east-west intersection is 20 m. 6c.The yellow light should be for 3 seconds so that the light has a reasonable go zone for the drivers.
 * Part B:**


 * Physics Talk:**

1a. w=15m Ty= 4 s V= 15 m/s a= 5 m/s Tr= 1 s

1b. GZ= v(Ty) - w GZ= (15)(4) - 15 GZ= 45 m

1c. SZ= v(Tr) + (v^2)/ 2a SZ= (15)(1) + (15^2)/ 2(5) SZ= 37.5 m

2a. GZ= v(Ty) - w GZ= (30)(4) - 15 GZ= 105 m

2b.SZ= v(Tr) + (v^2)/ 2a SZ= (30)(1) + (30^2)/ 2(5) SZ= 120 m

This intersection is dangerous because there is a dilemma zone.There is a dilemma zone because the person is going too fast if they slowed down then there would most likely be an overlap zone.

3. For the Go Zone it is about going through the intersection so the person driving the car does not have to move or react to brake.

4. It will not affect the Go Zone at all because when the car is in the Go Zone it does not have to stop or reaction but on the other hand, the Stop Zone will increase because a car may not be able to stop as fast as a car with new tires and brakes.

5.The reason is to eliminate the dilemma zones. It is to prevent accidents.

6. With the countdown method the cars will see they don't have enough time left to get through the light so they speed and that could be dangerous and cause an accident. The countdown affects the Stop Zone more because the cars will most likely speed up increasing both zones but more the Stop Zone. Once you are in the Go Zone you are good to go but if you are speeding and in either the Stop Zone or the Dilemma Zone then you need to make a split-second decision.

7a. Go Zone- 48 m Stop Zone- 52.6 m UNSAFE

7b. Go Zone- 72 m Stop Zone- 52.6 m SAFE

7c. Go Zone- 48 m Stop Zone- 48.6 m UNSAFE

7d. Go Zone- 48 m Stop Zone- 64.6 m UNSAFE

7e. Go Zone- 40.5 m Stop Zone- 43.1 m UNSAFE

8. No because the Zones are unrealistic because they change all the time.

1. The factors that affect the go zone are the speed of the vehicle, the yellow light time, and the width of the intersection. The factors that affect the stop zone are the human response time, the speed of the vehicle, and the negative acceleration. 2. To test your understanding of these zones you can give the student a model of an intersection showing the width of the intersection, the speed of the car, the drivers response time, the negative acceleration, and the yellow light time.You could verify these conclusions by working them out to see if the car would safely or unsafely make it through the yellow light. 4. This will help to know more about the STOP and GO zones because I will be able to estimate as to which zone I am in based upon the yellow light and I will be able to make a safe decision while driving.
 * Essential Questions:**
 * 3. The knowledge I have gained from the GO and STOP zones will help my driving safety a lot because I can understand when it is safe to make a yellow light by just a few simple calculations.

Fc=mV^2/r
=__Section 7: Centripetal Force; Driving on Curves__=

-A car swerving around a cliff -The tires are off the ground - It is about to fall off the cliff -The car is going too fast - It is going into the wrong lane -The car is not slowing down -There is no guard rail
 * What do you see?**

-The sign says to slow down because your car can not travel as fast in control when it is turning rather then going in a straight line and there is a turn coming up in the road. -The amount you should slow down is determined by the sharpness of the curve and the dangerousness of the curve
 * What do you think?**


 * Investigate:**

1a. I think that it would take path B since the car was rotating around a center and the string was making the car go in a circle, which once it was released, it would. 2a. The object would continue in a straight line. 3a. 4a. The metal washer is 18.5 cenimeters away from the center of the turn table. 6a. It took the metal washer 22 seconds for it to travel 10 revolutions around the turn table. 6b.60/22= 2.72x 10 the metal washer will travel around the turn table about 27 times in 1 minute. 6c.10 revolutions / 22 seconds = 2.2 seconds for the metal washer to travel around the turn table once. 6d. Because when you pick 10 revolutions you have an better average also it is harder to time one revolution then it is to time 10 and then take the average. 7a.119.32cm is the circumference speed= distance/time speed= 119.32/2.2 speed= 54.24cm per second 7b.16.63 seconds to go 10 revolutions 16.63/10= 1.66 seconds for 1 revolution

speed= distance/time speed= 119.32/1.66 speed= 71.87cm per second 8a. The sandpaper will give more friction so the metal washer will be able to stay on the turn table at higher speeds without falling off the turn table. 8b. It took 11.82 seconds to travel 10 revolutions. Which means the 11.82/10 = 1.182seconds to travel around the turn table once. 2.2-1.182=1.018 seconds faster then without the sand paper. 8c. speed= distance/time speed= 119.32/1.182 speed= 100.95cm per second 8d.11.35 seconds for the metal washer to go 10 revolutions at the speed it just falls off the sand paper. 11.35/10= 1.135 seconds for 1 revolution speed=distance/time speed= 119.32/1.135 speed= 105.13cm per second 9a. The smaller the circle is the greater the maximum speed can be.

-Force: a push or a pull -Newton's first law of motion states that an object in motion will stay in motion at a constant speed and travel in a straight line unless a force acts on it. When you let go of the string, the car traveled in a straight line unless a force acts on it. - When you released the string the car goes straight because no force is acting on it. - The string is pulling force into it and that is what keeps the car going in a circle. -When a car is on a road if you eliminate the friction of the road and the tires (icy road) the car will not be able to turn -**Centripetal Force:** a force directed toward the center to keep an object in a circular path -**Centripetal Acceleration:** a change in the direction of the velocity with respect to time -Changes of velocity while traveling in a circle with respect to time are called accelerations. -Velocity can change with a change of direction too -Centripetal Force is needed to travel in a circle but for a car you need friction to do that -A car traveling in a circle is accelerating because its changing direction.
 * Physics Talk:**

__**Three Forces that make an object move in a circle:**__ - Tension Force - Normal Force - Frictional Force


 * Physics to Go**

1. 6400000/24= 1675.52 km/h 1675.52 x 1,000 = 1,675,520 / 3600 = 465.42m/s

2. 1.07x10^5km/hr

3. v= 60 r/s r=15 cm 60^2/ 15= 240cm/s= .24m/s

4a. The more friction needed for the car to be safe 4b. The car will have to move slower and have more friction while turning. 4c. If the curve is tighter and there's slippery roads the conditions will be very dangerous.

5. The clothes in a spinning dryer have a force on the outside that is pushing in that keeps the clothes moving in a circle. **Normal Force**

6.?

7. The driver can do all they want to try and make a good turn with the wheel but if the curve is too tight then no matter what the automobile will not make it safely around the turn.

8. v=270m/s r=1000m a(c)= v^2/r a(c)= 270^2/1000 a(c)=72.9 m/s^2

10. Centripetal forces act on race car drivers and they pull them around the turns.

11. They are especially dangerous because people don't realize that the tighter the turn gets the harder it is to make because you need more friction.

12. You would end up in the other lane because there would be no force pulling you in. If the curve bends to the left then you will end up in the ditch on the side of the road.