Minute Physics- Tides

Recently in Physics we (the scholars) have been reintroduced to tides. This reintroduction included the reasoning behind tides and why they occur. The past few weeks I have found Minute Physics on Youtube extremely helpful which is why i chose this source. This source recaps what we have recently learned, beginning with why there are two high tides and two low tides a day. The video goes on to  explain why if the moon were to get any closer to the Earth the forces from Earth wound cause rocks on the moon to move and result in falling on the Earth.  

Unit blog Reflection

Do not be afraid of the title of this unit, it only applies to part of this unit.

In Unit 2 my class and I entered the world of Newton’s second law, which incorporated falling through the air which is SKYDIVING (has air resistance), free fall: falling straight down, throwing things straight up, falling at an angle and throwing things up at an angle. We also subconsciously learned how Newton’s first law and Newton’s second law relate.

Acceleration is the rate at which velocity changes with time. (image) Acceleration is produced by force. These concepts are connected using mass, thus the parts of Newton’s second law. Newton’s second law is a=f/m, which translate to acceleration is directly proportional to force and inversely proportional to mass. Therefore, if force were to increase acceleration would increase and mass would decrease. The acceleration applied to an object depends on applied forces, friction forces, and the inertia (unit 1) of an object. The amount of inertia an object has depends on its mass. The more matter an object has the more inertia. Mass corresponds to our intuitive notion of weight, but weight and mass are not the same thing. Mass is the quantity of matter in an object. It can also measure the inertia that an object exhibits in response to any effort made to start it, stop it, or change its state of motion in any way. Weight is the force upon an object due to gravity. In the absence of acceleration mass and weight are directly proportional. This means that if mass were to increase so would weight. When expressing the equation for acceleration one must also know the units, which stay constant: Newton’s (N) for force, kilograms (kg) for mass and meters per second squared (m/s²) for acceleration.

Acceleration= net force/ mass or a= fnet/m

With the application of direction the result will be a combination of speed change and deflection. Remember: the acceleration of an object is always in the direction of the net force. (i.e.- applied in the direction of the objects motion, a force will increase the objects speed)

Newton’s second law provides an explanation for Galileo’s concept of why objects of various masses fall with equal accelerations. A falling object accelerated towards the Earth because of the gravitational force of attraction between the object and Earth. An object is in a state of free all when the force of gravity is the only force action on it meaning air resistance is negligible. The greater the mass of an object the greater the gravitational force. Acceleration of an object depends not only on the force but also on the objects inertia. Remember: Force produces acceleration and Inertia is resistance to acceleration

The acceleration due to gravity is symbolized as g. Therefore g=f/m

Newton’s laws apply for all objects, whether free falling or falling in the presence of resistive forces. The idea of net force is important when discussing acceleration. In cases in which air resistance can be neglected, the net force is the weight because it is the only force. In skydiving once you leave the plane there are only two forces acting on you: the Earth's gravity pulling you straight down, and friction with the air. The friction with the air adds up to push you in the opposite direction of the direction you were originally going in. Air resistance increases as your speed increases, so when you drop you are moving slowly and gravity is stronger than the air resistance so you begin to speed up, accelerating towards the ground. However the faster you drop, the stronger the air resistance is and so eventually you are moving so fast that the air resistance is equal in strength to gravity and you no longer accelerate. You have reached terminal velocity. Why does body position come into it? Air resistance also depends on the shape of the object, so by tucking in your arms and legs you can reach a faster terminal velocity than if your arms and legs are spread out. Air resistance is affected by speed and surface area, which are directly proportional. As you fall you speed up and it causes you Fnet to decrease. After you open your parachute you Fair resistance increases, your net force is no longer on, and both your acceleration and velocity will decrease. Your major goal when skydiving is to be in equilibrium. The purpose of a parachute is to slow you down so you don’t gain more and more speed and implode the earth. A free falling object is an object that is falling under the sole influence of gravity. Any object that is being acted upon only by the force of gravity is said to be in a state of free fall. There are two important motion characteristics that are true of free-falling objects: Free-falling objects do not encounter air resistance, and all free-falling objects accelerate downwards at a rate of 9.8 m/s² (often approximated as 10 m/s²). Because free-falling objects are accelerating downwards at diagram of its motion would help in depicting acceleration. The fact that the distance that the object travels every interval of time is increasing is a sign that it is speeding up as it falls downward. The distance formula, for falling, is D=1/2(g)(t)2 and the velocity is V=(g)(t). Our study took us next to throwing things straight up and down. This concept asked for us to useD=1/2(g )(t)2 to find the time that the ball is in the air. However, we can only use this formula for the fall not the rise so we must double it to find the total time in the air. These concepts can be hard but one must draw pictures, which make it easier. The next section we learned was falling at an angle. A new equation was needed for the horizontal velocity, and it was V=d/t. We also need to know that the horizontal velocity does not effect the time something is in the air that is only affected by height/ distance upwards and downwards. During this section we learned that to drop a package we must drop it before the target as the plane moves. To find the where the package will land we had to use both the horizontal and the vertical equations to find where the package would land, if there is no air resistance on the box on its way down. Finally, we studied throwing things up at an angle. Three equations were needed for this section from before to find the horizontal and vertical velocities. However, we needed to find the actual velocity of the object by using the Pythagorean theorem, which says a²+b²=c². The equations we needed to memorize in order to understand this were triangle tricks. They are a triangle with two sides of 1 the third will be 1 root 2 which equals 1.41. If we multiply all by 10 or 100 we would just have 14.1 or 141. The last triangle is a 3,4,5 triangle which has two sides that are 3 and 4 and the hypotenuse is 5. The downward acceleration will always be 10m/s² and at the top of its path, the horizontal velocity will still continuing to push it forward. I found a lot difficult during this unit. My difficulties stemmed from lack of full concentration. I didn’t full understand free fall and throwing things up at an angle. Adding the component of horizontal and vertical were where I struggled the most. I overcame these difficulties by trying more examples and revisiting the videos. I huge help for me were my peers mainly Kaylee and Elise who were able to bridge gaps for me as well as me for them. My problem solving has definitely improved this unit. I believe I have gotten better because I’ve had to tweak my learning style with these new and different concepts, which expound off one another. My effort has also improved because I’ve been doing more than I’ve been doing, I engage more in class whether its too help myself or to help and a classmate. I’VE realized that when I know what is going on I have a way better experience because I can explain to others. My learning style has gotten deeper for I have realized I need to dig deeper to actually understand what is going on. My goals for the next unit are to use my prior knowledge with this unit and make more connections. I wish to improve my quiz grades by studying differently and attending conference period where maybe I can also receive helpful hints and ways to grasp the information to a fuller extent. One may connect this to everyday life because of sports. I am really into sports basketball and volleyball in particular. These sports I have realized are based on angles and arcs and someone this has also clicked for me on the courts. This unit also reflects baseball and how certain angles can help baseball players hit home runs.