(no subject)

[chess]

Exams are of the evil.

Had Physics and Economics. Everybody agreed that the Physics paper was unnecessarily difficult and incomprehensible. Nobody answered the first four-mark question in any kind of reasonable manner. (Picture of tennis ball resting on horizontal tennis racket. First question - draw the two forces on the ball. Nice and simple; weight down, normal reaction up. Next question - Every force has an equal and opposite force. Explain what the opposite forces are for these forces and what object they act on. Four marks. Wrote something incomprehensible about corresponding forces on the racket, thinking 'butbutbut, these *are* their own opposing forces'...) As for Economics, wrote an awful lot of junk, needed all 26mins of my extra time and still don't feel that I satisfactorially answered anything. Questions were terrifically vague and woolly. Couldn't think up any decent 'evaluative phrases' or 'conclusions' for them because they weren't the kind of thing that concluded properly. Didn't feel that what I wrote was an answer to the questions, but couldn't figure out what it was that they were actually looking for.

So, bad.

Exams over now. This should be of the good. Am still stressed. This is somehow Wrong.

People at school say I am immune to exams. Tend to forget about being stressed when looking after people who are about to explode due to being stressed, but am not immune, so bah.

I really do write these entries in a voice that isn't my own, these days. Is most upsetting.

Comments

[passage.livejournal.com]

No, remember Newton's 3rd law:

For every action force there is an equal and opposite reaction force. Action and reaction act on different bodies.

Yu can't have a force and it's reaction force both acting on the ball.

The paired force for the balls weight is the weight force exerted by the ball on the earth (totally negligable due to the small mass of the ball and the enourmous mass of the earth). The reaction to the racket pushing up on the ball is the ball pushing down on the racket[1] (although I find it easier to think of it in terms of the action being the ball pushing down on the racket, but mathematically (and physically) it makes no difference, it's just one kinda makes sense to me ;-)).

I'm quite disturbed that Naath got this wrong as well. Why back in my day a Cambridge physicst would never yaddayaddayadda...

(I guess your school didn't keep repeating NIII to you with the voice rising in volume for the last clause.)

Neil

[1] I keep wanting to spell 'racket' with a 'q', am I going mad?

[foreverdirt.livejournal.com]

*Has learned something new*

Thank you.

[passage.livejournal.com]

<bows>

Glad to be of service.

Incidently I was recently somewhat disturbed to discover that Newton's 3rd law isn't actually true. It only holds for forces whose line of action is along the line connecting the particles concerned, hence it is true for gravity and electrostatic forces, but not neccessarily for magnetism.

Neil

[ylla.livejournal.com]

[1] I keep wanting to spell 'racket' with a 'q', am I going mad?

No, just being British.

I think the usual British spelling for the thing you play tennis with is 'racquet' - it's definitely not wrong, although racket is right too.
The big shouty noise is always a racket. [1]

They're probably both spelt 'racket in America.

[1] Unless it's a row, or something else similar. [2]
[2] Eeep. I caught footnotes...

[passage.livejournal.com]

Phew. My instincts were right afterall then ;-)

Thanks

[chess]

Contagious, aren't they?

[chess]

Ahwell, at least I got half of it right then.

You're not mad; I desperately want to spell it 'racquet' too.