Wrong C7. The rate of free-fall acceleration can be attained by 1) an object falling with no resistance, as you and Chandler think is the ONLY way or 2) with no NET resistance, where multiple forces act against each other and cancel each other out, a possibility which you and Chandler don't allow for. And freefall is not always straight down....[Additional comments followed]
@chrismohr -- I see that I am not on the list of those invited to comment
... but here goes anyway.
Probably the central issue in understanding freefall accelerations and accelerations more than free fall is the need to identify the "free body" on which forces are acting. In other posts here and elsewhere I have used an alternative description of "sub-system boundary". I note that you used systems terminology as part of the explanation in your video #18. At that point you referred to an identification of a system by a truth movement supporter. That definition of system was wrong as you identified and your identification of the sub system under discussion is correct. (To guard against potential nit-pickers I make both those comments strictly in the context of what you were presenting.)
In a recent post C7 states:
The no-net-resistance cannot apply during free fall acceleration nor can the acceleration be anything other than gravitational acceleration during the 100 feet of free fall. You quote Mr. Chandler saying that in a body in free fall, there are no internal forces but you don't understand what that means...
In a recent post I quoted the highlighted portion drawing attention to the word "internal" and posted this terse comment:
Internal???
Did Chandler say that?
C7 has so far not answered that query of the alleged use of "internal" by Chandler.
If Chandler did make that statement he is wrong. Obviously wrong and at an elementary level of physics.
Let me illustrate two points by a simple example. I put you inside an enclosed box say one metre square and 1.8 metres high. As you stand in the box your head is in contact with the top and your feet naturally in contact with the bottom. (I need the head to top contact to eliminate some second order effects which may be raised by third party sceptics at a later stage -- if we get that far.
) I give you a tennis ball which you hold in your right hand. I then drop the box including you and the ball from the top of a tall building.
The box with you and the ball inside it will enter free fall minus the effect of air resistance.
You inside the box throw the ball down so it travels to and strikes the floor.
Point One: Whilst you are engaged in the throwing motion which is accelerating the ball up to throwing speed the ball is accelerating downwards faster than free fall.
You extend you arms sideways and press on the side walls of the box.
Point Two: You have exerted internal forces despite the (alleged) Chandler claim that there are no internal forces.
Test Question for the lurkers: When you release the ball and whilst it is travelling downwards towards the bottom of the box what is its acceleration?
The box and contents comprises a discrete system. What happens inside that system has no effect on the motion of the system relative to its external context and the rapidly approaching ground below.
If anyone in addition to C7 or MM wants to correct any of these observations, please do so. Tri? Shek? Oystein? You know me; I'll make corrections when I'm shown to be wrong....
I have watched the video. Given that it was intended as one of a series intended for an audience of lay persons I think it does a good job. Sure there are one or two points where the physics pedant in me would suggest a different emphasis of explanation. But you could go for ever with nit picking fine tunings. I saw no significant errors in this first re-watching.
