Chapter+2

=Section 1=

Learning Objectives
- Describe Galileo's law of intertia toc - Apply Newton's first law of motion - Recognize internal mass as a physical property of matter - Use examples to demonstrate that speed is always relative to some other object. - Explain that the speed of an object depends on the reference frame from which it is being observed.

What do you see?
The guy is running really fast and gaining a lot of momentum, then kicks the ball and because of all the momentum and speed he has, the ball goes really far. Also the other guy has no momentum and the ball goes nowhere. Also there's a mouse and a ladybug that are trying to hit a soccer ball but are too little.

What do you think?
1. Figure skaters keep moving across the ice at high speeds for long times while seeming to expend no effort because of friction, and it resists the object from moving across the service. Ice has very little friction so the skaters are going to be able to coast. 2. The soccer ball continues to roll across the field because the ball is hit by a force that is so much greater.

Investigation
1a. Starting Height - 30 cm 1b. Vertical/Recovered Height - 29 1/2 cm.

2a. If you start it half way, on the other side it will be a little less than half way down, around 19.5ish.

3a. Starting Height - 20 cm My prediction was close, but it wasn't right because there was an uncertainty. 3b. Vertical/Recovered Height - 20 cm (random error) In terms of its starting and recovering height, they started and ended up as the same height. There may have been random error in the ruler or in putting your finger and measuring in the incorrect place.

5. No because it loses energy because of the friction and will never have the same amount. 5b. The ball would most likely roll pretty far. 5c. If there was no friction then the ball would keep rolling on the track. If there was someone pushing on it or something like that, then it would also keep rolling.

Do Now 12/9/11
1. If a skateboarder starts at the top of a 4 meter tall half pipe and travels around to the other side, with gravity but no friction, on the other side it will reach almost the exact same place at 4 meters. 2. If friction is not ignored, he will reach a little lower than what they started off as, around 3.9. 3. This scenario illustrates Newton's 1st Law of Motion by an object in motion will stay in motion because there is no force. If there is a force, it won't go all the way.

Physics Talk
Inertia - the natural tendency of an object to remain at rest or to remain moving with constant speed in a straight line very similar to Newton's first law and there's an absence of unbalanced force

1 kg @ 10 m/s 2 kg @ 5 m/s 5 kg @ 2 m/s 10 kg @ 1 m/s (larger the mass the higher the inertia)

Frames of Reference 5 mph - in reference to who's carrying it 0 in reference to the person looking it's 5

car going 70 mph -> <--- car going 55mph it looks like the 70mph car is going 125mph (from both perspectives)
 * Opposite Direction**

car going 70 mph > to the 70mph driver, 55mph car is 15mph slower car going 55 mph > to the 55mph driver, 70mph car is 15mph faster
 * Same Direction**

Newton's first law of motion tells you that when the athlete releases the javelin, the javelin will continue at the same speed. Objects in motion stay in motion unless a force acts on them. Acceleration occurs during starting, stopping, and changing direction.

1. Inertia is the natural tendency of an object to remain at rest or to remain moving with constant speed in a straight line. 2. An object in motion will stay in motion at a constants speed and travel in a straight line unless a force acts on it. 3. An outside force needs to act on it. 4. What stops the ball from moving could be an outside force like a person or there's too much friction now maybe. 5. The bigger mass will have the greater inertia. 6. Its important because the speed of the object has to do with it. = = =Section 2=

Learning Objectives
Give examples of distance, time, speed and acceleration. Differentiate between instantaneous speed and average speed. Recognize when motion is accelerated. Calculate average speed and acceleration.

What do you see?
In one picture, I see a guy walking slowly so his footsteps are very close together and there are many of them. In another, I see the same guy running so his footsteps are farther apart and there aren't as many.

What do you think?
100 mi/h and 45 m/s are different because the first one is miles per hour and the second is meters per second, so they're measured at different units of measurement.

Physics Talk
i'm doing the physics talk in my notebook wiki is being weird and not working for me

Checking Up
1a. A constant speed is when the ticks are evenly spread apart over time. 1b. Positive acceleration is when the ticks are close together then eventually get farther and farther spread apart. 1c. Negative acceleration is the opposite, and they start of spread apart then get closer together.

2. 8m/s. 3. The difference between instantaneous and average speed is that average speed is the distance traveled divided by the time it took to travel that distance. Instantaneous speed is the speed measured during an instant the speed as the time interval approaches but does not become zero. 4. 10m/s/s

=Section 3=

Learning Objectives
Identify the forces acting on an object Determine when the forces on an object are either balanced or unbalanced Compare amounts of acceleration semi-quantitatively Apply Newton's second law of motion Apply the definition of the Newton as a unit of force Describe weight as the force due to gravity on an object.

What do you see?
A guy is pushing a ball with a noodle and the ball is going faster so the person has to go faster with it. The contact with the ball is maintained so she has to move faster to keep in contact.

What do you think?
Force is a push or a pull on an object. The mass of the balls are different, and a tennis ball will go faster because it's lighter and the ball with the bigger mass will be less effected by the force.

**Checking Up Questions**
1. Newton's second law is all about the equation f=ma 2. It would decrease the acceleration. 3. the gravity is always -9.8 so then the mass would equal whatever 30 divided by -9.8 is. 4. Your mass always stays the same and your weight would increase.

Physics to Go (did on paper)
 * 1-7, 10-12, 15

=Section 4=

What do you see?
Both apples are being dropped at the exact same time but the green apple is going horizontally, but landing at the same time.

What do you think?
force, air resistance, height

Checking up
1. Yes they will reach the ground at the same time as long as there's no air resistance. 2. Yes it's velocity remains the same because it doesn't change no matter what. 3. The ball's velocity at the highest point is 0.

=Section 6=

Learning Objectives
Provide evidence that forces come in pairs, with each force acting on a different object. Use Newton's third law to analyze physical situations. Describe how Newton's third law explains much of the motion in your everyday life.

What do you see?
The guy is kicking off the wall in his scrolling chair, so he's moving in the other direction fast. The wall is curved to show how he's pushing off.

What do you think?
You would tell them to apply force to the ground and you would push and go in the opposite direction.