Tides resource

This video provides a very clear and engaging explanation of tides and how the moon and the sun have to do with it. The creator of this video made a diagram of where the moon has to be when there is a high tide and low tide. The side closest to the moon will experience high tide because of the gravitational pull and the opposite side will experience the high tide as well because the earth is pulling on the moon as well as the moon is pulling on the earth. I definitely believe that this video helped me to see how the tides are effected by the moon. When the moon is full then the tides will be higher than normal and when it is a half moon the tides are lower than normal.

Unit 2 Reflection

Newton's Second Law:

Newton's Second law states that acceleration is directly proportional to force and inversely proportional to mass, or a=F/m. Whenever mass increases, the acceleration. When looking at mass vs. weight, weight=(mass)(gravity), or w=mg. and example equation of this is:

Skydiving:

Skydiving is an example of Newton's second law in action. Here is a diagram of what happens when you leave the plane:

In the last part of the picture, the skydiver is in terminal velocity which means they are going as fast as they possibly can but are no longer accelerating. After they reach terminal velocity they parachute goes up. Once the parachute comes out, the surface area increases as well as the net force. The velocity continues in the downward direction, but now the acceleration is in the upward direction. This means that the skydiver is slowing down. Then the skydiver hits terminal velocity again where the F air is the same as before but the skydiver is moving slower, because of the parachute. They are no longer accelerating, but are moving in the downward direction.

Free Fall:

Free fall is when an object falls, with no air resistance. An example of this that was shown in class is a penny and a feather were placed in a tube with no air in it. When the tube was flipped over, the penny and the feather hit the ground at the same time. The only force acting on a object in free fall is the force of gravity. The equation used to determine the acceleration in free fall is : a=fnet/m. When you are searching for the distance, you use the equation: d=1/2dg^2. And when you want to know the velocity the equation v=gt is used. 

Projectile Motion (falling at an angle):

Projectile motion is when something is thrown or dropped. An example is when you drop two balls on the ground. If you were to shoot a ball off a table and drop a ball of the same table at the same time, they would hit the ground at the same time. The only thing that matters is the height. The balls hit the ground at the same time, because they left from the same height. When a person jumps off a cliff you must know the vertical and horizontal distances, speed, and time. When determining horizontal you use the equation: v=d/t. When determining the vertical you use: v=gt or d=1/2gt^2. When you hit the ground, you realize that you took a curved path, because you are moving both vertically and horizontally. 

Free Fall (falling straight down):

Free fall is when something falls and the only force acting on it is the force of gravity. The main thing to know about free fall is that there is NO air resistance. The weight of the object falling in free fall does not matter, because the only force acting is the force of gravity. If you were trying to figure out how high a cliff is and the only information is that an object falls off of it and falls for 9 seconds. You would use the equation d=1/2gt^2. 

Free fall (throwing things straight up):

When you throw an object straight up, neglecting air resistance, the object stops at the top of it's path and falls back down. The balls acceleration remains constant the whole time. The acceleration is 10 m/s^2, even when the ball's velocity is 0 m/s at the top of it's path. If the ball starts off at 40 m/s then the next second will be 30 m/s and the velocity will continue to go down until it is at the top of it's path and then it will accelerate back down at 10 m/s^2. 

Free Fall Resource

In this video, a man explains exactly what free fall is. He preforms a demonstration with a heavy ball and a light ball. He drops the two balls and they hit the table at the same time. He then goes on to explain why this happens. The reason the balls hit the table at the same time is because they have the same acceleration.

Newton's 2nd Law Resource

This video was really helpful in understanding exactly what Newton means in his 2nd law. The demonstration of the balls being shot out of 2 tubes helped me see that an object with less mass will move quicker than an object with more mass. This video helped me see Newton's 2nd law in a real life scenario.

Net force and Equilibrium Podcast

Blog Reflection

     In this unit I learned about Newton's First Law, Inertia, Net Force, Equilibrium, Speed, Velocity, equation for a straight line, and Acceleration. I also learned different formulas and equations to go along with each of these concepts.

     

Newton's First Law and Inertia: At the beginning of this unit, the first things we talked about was Newton's First Law and Inertia. Newton's First law states that an object at rest tends to stay at rest unless acted upon by an outside force, and an object in motion tends to stay in motion unless acted upon by an outside force. Inertia is another way to refer to Newton's First Law. An example of Inertia is when there are plates on top of a table cloth and someone pulls the table cloth out from under the dishes and the dishes remain on the table. They remain at rest and don't move with the table cloth, because they were not being acted upon by an outside force. Inertia is occurring but you cannot say that the reason this happens if because of Inertia, because Inertia is a property. Another good way to think of Inertia is by saying things like to continue doing what they are doing, so if an object is at rest it will want to stay at rest. One more example of Inertia is if you throw a penny up in your hand it will land right back in your hand. There is no force that is causing the penny to move forward with the car.

   

 Net force and Equilibrium: Netforce is once or more forces acting upon an object at once. A force is either a push or it is a pull. So and example of net force would be the following:

This is an example of an object moving at a newt force of 10 newtons. Newtons is the measure of force. If the force of friction ( the amount of resistance) were to be 10N then the net force would be equal to 0N which would mean the object would be at equilibrium. If an object is either moving at a constant velocity or the object is at rest then it is at equilibrium because there is no force, or the force is equal. 

       

Speed and Velocity: Speed is how fast an object is moving. There are many ways to measure speed but in Physics the most common way is m/s. In order to determine speed, you have to use the equation which is distance/time.  Speed is different from velocity, because velocity requires a specific direction. Velocity is the speed of an object that is moving in a specific direction. In order to change velocity, there needs to be an outside force acting on the object. Another way to change your velocity is by changing direction. Changing direction does not change the speed though. An example of this is a race car rounding the corner at 90 km/hr. The car would continue at a constant speed but it would not be going at a constant velocity, because it is changing direction. 

Equation of a straight line: The Equation of a straight line is y=mx+b. The y in this equation stands for time and the m stands for 1/2 a and the x stands for time^2. So this equation could also be written as d= 1/2 at^2. 

     

 Acceleration:  Acceleration means an increase or decrease in speed. In order to find acceleration you would use the equation of change in velocity/ time. The unit used for acceleration is m/s2. 

 In this picture, it shows how the ball accelerates based on the height of the ramp. If you want to determine how fast an object is moving then you would use v=a (acceleration) x t (time). And if you want to figure out how far an object is going you would use the equation d=1/2 at2. Acceleration means how much the object is speeding up. In order to have a constant acceleration then the increase must be equal. For example going from 52 to 54 to 56 would be a constant acceleration, or going from 56 to 54 to 52. If an object is moving from 50 to 58 to 59 then it would not be constant. 

      Me as a Student  

       I think that the the most difficult part for me this unit was the equation for a line and graphing. After watching the video made by my classmates about graphing and equations, it made it much more clear. I took notes on that video and I understand when and why I use certain equations. I also reviewed labs and old notes to see where I used this equation. The lightbulb clicked for me when I re-watched the podcast on this topic, because they explained it in a way that made it easy for me to understand. They also had visuals which made it even clearer.

      I think that I have had a pretty good understanding of Physics so far this year. I have completed my homework, and I really appreciate the videos Ms. Lawrence made because they helped to hammer in the concept that we learned. I think that the blogs have been successful in helping us as students explain what we have learned. I think that I have put a lot of effort into making sure my blog posts are good, but I do think that there is room for improvement. One way I could improve my blog posts is by making them even more detailed and accurate. In Physics I see the use of creativity by coming up with scenerios that Physics can be applied to such as a car driving around a race track. I think that I do take my time working on problems, but I could be even more detailed in my answering. My goals for the next unit is to make sure I completely understand a concept before taking a quiz on it. I also need to work on showing all of my work on a quiz. I could do this by writing out the formulas and all the information needed on a problem even if it seems unecessary before completing it. I think that I also need to participate and ask more questions in class. 

Making Connections

      

    Physics is seen in everyday life. A few examples of where is see Physics include driving down the road and in sports. When I drive to school and we turn out of my driveway onto cane creek road, we are experiencing a change in acceleration because we are both turning and speeding up. We are not moving at a constant velocity though when we are moving, because we are changing speed and direction. During field hockey practice I see Physics all the time. When I hit the ball it is not longer at rest because I hit it with an outside force. The stick causes the ball to move until the grass (another force) causes it to slow down and eventually stop. If the ground was completely flat and even then the ball would continue to move because an object in motion tends to stay in motion unless acted upon by an outside force. 

Constant Velocity Vs. Constant Acceleration

     The purpose of this lab we just finished was to deepen our understanding of the difference between velocity and acceleration and to learn how to solve for how fast and how far something is going using the equation of a line. We also learned how to translate the equation of a line into words then numbers.
During the lab it became clearer the difference between constant velocity and constant acceleration.Constant velocity means that the object is moving at a constant speed. There is no acceleration or change in speed. Constant acceleration means that the object is speeding up or slowing down at a constant speed.
    In the lab we rolled a marble down a flat surface to determine the constant velocity, we did this by making a mark of where the ball was every second and then measuring the distance between the marks using cm. We did the same thing to find the acceleration of the marble but it was on a ramp instead so the marble was constantly speeding up.
    I learned that if something is moving at a constant velocity, it cannot be moving at a constant acceleration because that would mean constantly speeding up and in order to have a constant velocity it needs to be at equilibrium. The formula that is used to determine constant acceleration is a= the change in V/ time. The equation for constant velocity is v=distance/time. Another distinction between constant velocity and constant acceleration is the line graphs. A line graph for constant velocity would be a straight diagonal line whereas a line graph for constant acceleration would be a curved line that becomes steeper as it accelerates. The line graph and the line equation support my data because it shows how constant velocity has an even distance between every mark (second) and for acceleration the graph shows how the ball sped up and covered more distance in less time.
    One important thing that I learned from this lab is how to take a line equation and translate it into words such as distance and time. I am sure that I will see this equation much more throughout Physics class this year. This lab also helped me with the other equations we have learned such as the equation for how fast and how far something is going. Another thing that became more clear is how to determine whether something is at constant velocity or if it is moving at constant acceleration. This became much more clear to me when we did the experiment with the marble on the table. One other thing I learned is how to graph my results and figure out the equation of the line.