Newtons Second Law

Newton's second law podcast

Unit 2 reflection

In this unit I learned about the physics of motion. Some of the key topics discussed during this unit were free fall, Newton’s second law of motion, projectile motion, and air resistance. We began the unit with Newton’s second law which states that forces is directly proportional to acceleration and mass is inversely proportional to acceleration. This definition is explained through the formula a=f/m. Furthermore, we learned about free fall. We learned that in free fall gravity is the only force acting upon a falling object. Therefore, all objects fall at the same acceleration of 9.8 m/s^2 . To calculate free fall, we were taught the equation, d=1/2gt^2. Transitioning from free fall, we learned about projectile motion. Projectile motion introduces both horizontal and vertical motion. Horizontal motion has a constant velocity and uses the equation, V=D/T. Vertical motion has constant acceleration and uses the formula d=1/2gt^2. The horizontal and vertical motions of a falling object create a parabolic path.  Finally, we learned about air resistance. With air resistance, we learned that as an object falls, air resistance increases with speed and decreases with acceleration until the object reaches terminal velocity. To calculate air resistance, you use the formula Fnet/M=A. Also, both weight and surface are affect air resistance. The more weight, the more air resistance is required since it has a greater downward force. The more surface area, the more air resistance because more air molecules are hitting the falling object and therefore a greater upward force is being applied to the object.  As a conclusion to the unit, we learned important applications of these physics resources. For instance, we learned about the fundamentals of air resistance through sky diving. As an example, a sky diver increases air resistance and speed until he reaches terminal velocity. When he pulls his parachute, he gains more surface area and thus a higher air resistance. Because there is more upward force acting upon the object, the sky diver slows down. Another example of physics in real life is baseball. Baseball shows us the application of projectile motion. When the ball is hit it forms a parabolic path. The horizontal velocity of ball remains the same as what the batter hit the ball with. The vertical velocity changes as decreases in velocity when it rises and then increases in velocity when it falls. To calculate the actual velocity which the ball is initially traveling you can use the formula a^2+b^2=c^2.

The most difficult challenge I faced this unit was retaining the information from the previous lessons and building on those previous lessons to learn new principles about physics. Specifically, the application of the formulas and the wording of my answers proved to be difficult for me.

I overcame these difficulties by practicing with the application and understanding the process of the formulas.  I will also force myself to be very specific when answering discussion questions as well as be very careful in my word choice.

Free Fall in tennis

In this picture, you see a girl setting up her serve by throwing the ball in to the air. This picture shows the real life application of free fall. When the ball leaves her hand, it gradually decreases from the starting velocity which she threw it by ten meters per second until it reaches V=0 m/s or the highest point of its path. It retains a constant acceleration since gravity is the only force acting upon the object. Thus, when it reaches its highest point, the tennis player then hits the ball into the opposing court. This picture shows a tennis ball that has reached its highest point. If the tennis players wishes to calculate how high the ball will travel, she could use the distance formula, d=.5gt^2. If the tennis player allows the ball to fall naturally, it would increase 10 miles per second until it reaches the ground, following the same path which it was thrown.

Brainiac - Do heavy objects fall faster than light objects ? Aristotle ...

This physics video is really helpful in understanding free fall in the absence of gravity. They perform some really cool experiments and clearly show the process of their results.

Brainiac - Do heavy objects fall faster than light objects ? Aristotle ...

This physics video is really helpful in understanding free fall in the absence of gravity. They perform some really cool experiments and clearly show the process of their results.

Brainiac - Do heavy objects fall faster than light objects ? Aristotle ...

This physics video is really helpful in understanding free fall in the absence of gravity. They perform some really cool experiments and clearly show the process of their results.

Brainiac - Do heavy objects fall faster than light objects ? Aristotle ...

This physics video is really helpful in understanding free fall in the absence of gravity. They perform some really cool experiments and clearly show the process of their results.

Brainiac - Do heavy objects fall faster than light objects ? Aristotle ...

This physics video is really helpful in understanding free fall in the absence of gravity. They perform some really cool experiments and clearly show the process of their results.

Brainiac - Do heavy objects fall faster than light objects ? Aristotle ...

This physics video is really helpful in understanding free fall in the absence of gravity. They perform some really cool experiments and clearly show the process of their results.

Brainiac - Do heavy objects fall faster than light objects ? Aristotle ...

This physics video is really helpful in understanding free fall in the absence of gravity. They perform some really cool experiments and clearly show the process of their results.

Brainiac - Do heavy objects fall faster than light objects ? Aristotle ...

This physics video is really helpful in understanding free fall in the absence of gravity. They perform some really cool experiments and clearly show the process of their results.