Newton's second law stated that acceleration is directly proportional to force and inversely proportional to mass. In simpler terms, this basically means that as the acceleration goes up the force will increase as well and the mass will decrease however if the acceleration decreases the mass is increased. In formula form, it is written as a = F/M, where F is the force and M is the mass.Another part of Newton's Second Law was the fact that mass and weight are not equal. In order to find the mass of and object you simply divide the weight by 9.8 (rounded to 10) or to find the weight of something you multiply the mass by 9.8 (rounded to 10). A simple formula to remember for this process is W=GM. Where the W is representing your weight, the G which stands for gravity is the 9.8 (rounded to 10) you multiply or divide with, and the M is your mass.
Sky Diving
In our sky diving lesson, we learned immediately that the speed that an object travels in the air effects your air resistance in a manner that is very similar. In fact a persons speed and air resistance are directly proportional to one another. This will happen until the object that is in the air reaches a terminal velocity (constant speed). In this picture, we see a picture of a man sky diving. In the (a) step, we see he is jumping out of the plane from rest so his force is only 980N, which looks sort of like 9.8 (force of gravity). As he is falling he begins to accelerate because as we stated earlier in Newton's Second Law, force is directly proportional to acceleration. In step (c), he is still increasing acceleration and his velocity and acceleration are all going downward. However, in the (d) step, when he opens up his parachute, his velocity is still going downward, but his acceleration is now going upward. Don't let this confuse you though. All this means is that he is beginning to slow down. He is going to continue to slow down until he slowly reaches terminal velocity again. With more air resistance now hitting the man due to the parachute, his speed steadily drops.Free Falling
In free fall, their is absolutely no air resistance, there for gravity is the only force action on any falling object. Knowing this, we know that the weight of an object no longer matters, because gravity is the only force pushing on the object which gives us 9.8 (rounded to 10). So if you were to drop two things from an equal height in free fall, whether a feather and a coin or two balls of different mass, they will hit the ground at the same time.
Throwing Things Up
This is a video that my group made about throwing things up in the air. Just remember this is how you would typically solve for one of these problems.
Projectile Motion
In projectile motion, there are two terms you need to know:
- Vertical Distance: has a constant acceleration (10m/s^2). We use the formula d=1/2gt^2. Vertical velocity is basically the height, and the height determines time.
- Horizontal Distance: always remains with a constant velocity because it has no force. We can calculate horizontal velocity by using the formula v=d/t
My Problem Solving Skills and etc...
This was a tougher unit for me because it was alot of things you had to know to fully understand Newton's first law. Saying this, I tended to get frustrated alot, even in group project I started to shut down when I didn't understand a problem, however now i understand it due to the several labs that we did in this unit. The videos that I watched on my own also helped me alot. My goal for next time is to never give up, even when the work load seems to get intense, I have to continue to work at it and ask several questions.
