Questioning Qualifications: Me Venting.

[Incongruent]

So there have been other mistakes in the past (polar ice caps are not salt water, Triple Beam Balance measure relative weight not mass, etc.) but this is unreasonable:

 

[OnionGreenPepper]

What do you find unreasonable?

 

[Incongruent]

Rockets operate on thrust not lift.

 

[tim cubbedge]

So what's your point?

 

[rharshberger]

Meh...

 

[markkoelsch]

Rockets operate on thrust not lift.

Same thing kiddo. You want to argue semantics, and they are trying to teach you something.

 

[cbrarick]

lift, thrust, spitting in the dark. Don't much matter what you call it, if you don't have it, everyone is going to laugh as your bird sits on the pad and smokes.

Just sayin'

 

[Incongruent]

How about "the ice caps are made of salt water"? In that case it was not semantics, they were trying to teach us that the polar ice caps were made saltier water than the surrounding oceans.

And if they use an experiment to demonstrate something other than what the experiment actually shows, is there a point in wasting time and effort on the experiment? Such as using a balloon inflating on the reaction between baking sofa and vinegar to demonstrate an imperfect system when the primary factor in decreasing mass is the increasing volume which increases buoyancy. And if you calculate the mass of the air that would be in the increased volume, you get the approximately discrepancy. (Imperfect measurements yield imperfect results.)

 

[markkoelsch]

First, not to get political, but many educational items are being bent to meet a political agenda these days.

Secondly, I still believe you are arguing semantics about the thrust versus lift thing.

How old are you?

 

[Incongruent]

The political agenda (for Texas) is TEKs. That's a list of everything to cover during the year and is everything that will show up on final exams. I've assumed that they're correct, but I will go check when I have time.

I'm 13.

I'll cover the other points you made later — school.

 

[RocketFeller]

It may be just semantics, but I think that Incongruent is right. Lift is generated by air flowing over a wing/lifting body, where thrust is a propulsive force. They could have just used the generic term "force", but lift is not really the proper word in this case.

 

[grouch]

It never fails to impress me how awesome 13 year olds are.

 

[tightwad]

I would pick "C". What did you pick?

 

[llickteig1]

Life is going to be very hard if you sweat ALL the small stuff. It is hard to remember that everyone else is not perfect.

 

[markkoelsch]

Life is going to be very hard if you sweat ALL the small stuff. It is hard to remember that everyone else is not perfect.

Lance, you are so terribly right. Worry about things that matter.

 

[grouch]

At 13, it all matters.

 

[shreadvector]

https://www.grc.nasa.gov/www/k-12/VirtualAero/BottleRocket/airplane/rktfor.html

https://www.grc.nasa.gov/www/k-12/VirtualAero/BottleRocket/airplane/rktwt.html

https://www.grc.nasa.gov/www/k-12/airplane/forces.html

 

[shreadvector]

https://www.imdb.com/title/tt0387808/

 

[paulm]

F=ma, newtons are a force and gravity is an acceleration. So F/a=m, mass, not F. The op says F/a=F.