Unit Blog Summary –
Unit two
What did I learn?
In this unit my understanding of the material leapt off
the page, starting out as formulas it crept its way into the real world. This
unit was all about how things fall. I learned the difference between free fall,
and falling with air resistance, and most importantly how acceleration can be
easily measured. The main topics we covered were free fall, Newton’s second law,
falling with horizontal velocity, and sky diving. Free fall set the stage for
the following units, as it created a base understanding of accelerating downward.
We then combined lessons from unit one when we discussed falling with
horizontal velocity, as it reminded me of the hovercraft, moving at constant
velocity. The unit picked up with the Introduction of Newton’s second law,
stating that acceleration = force / mass. This understanding allowed for the
top of the pyramid to be built, sky diving integrating free fall, air
resistance, Newton’s second law, and falling with horizontal velocity into one.
What are some things students
forgot while working on this unit?
- That air resistance is proportional to speed and surface area
- That horizontal velocity does not affect time in air
- That when you are accelerating in the opposite direction of your velocity you are slowing down
- That you cannot be accelerating while at equilibrium
Formulas from the Unit
- To find acceleration -Acceleration = Force / Mass
- To find distance while in free fall-Distance = ½ 9.8 meters per second per second (time) ^2
- To find velocity- velocity = 9.8 meters per second per second (time)
- To find actual velocity of an object that is moving forward while falling off a cliff or any other elevated object- speed = square root of horizontal velocity squared + vertical squared
- To find Net force while falling- Net force = f air – f weight
How is this relevant to
the real world?
- A few weeks back I listened to a fishing podcast addressing swinging salmon flies. The podcast brought moving at a constant horizontal velocity into play, as well as how flies sink. This made me think of air resistance while falling. This Showed that not only is physics in fishing but that fishing can be a great teacher of any pursuit. The drop of the fly is very similar to the problems we ran in class of the package being dropped from a plane.
Video- on free fall, with two fabulous actors.