Question on gravity?

[Hobbiez]

If we are given Displacement s = ut + (1/2)(at

[Ultramega]

Paging for Sir Isaac Newton.

[Requiemdk]

It's just a matter of manipulating the equations. The desired result does not have "u" in it, so it's most natural to try to eliminate that from the 2 equations that you'll get from your data. Btw this is of course assuming that the initial velocity, "u", is the same for both sets of data, and that the only force acting on the object in the experiment was its own weight, i.e. its acceleration is g alone, otherwise this would not be possible. Anyway, see the attached image.

 

[inline eqn.gif]

Edited June 28, 2008 by Requiemdk

[Cavver]

need differtialtion ?

[Remus325]

Imagine you dropped a ball with initial velocity u = 0. Let s1 denote the distance covered after time t1 and let s2 denote the distance covered after time t2

 

Then you have s1 = (1/2)(gt1^2) and s2 = (1/2)(gt2^2)

 

=> 2s1t2 = g(t1^2)t2 ---- (1) and 2s2t1 = g(t2^2)t1 --- (2)

 

take the difference between the two eqns above (i.e., (2)-(1)) and you have

 

2(s2t1-s1t2) = g(t1t2)(t2-t1)

=> g = 2(s2t1-s1t2)/(t1t2(t2-t1))

 

QED

[Requiemdk]

No differentiation needed here - constant acceleration = kinematics, which makes things easy with the 4 standard formula with v, s, u, a, t. Just use the equations for kinematics (the one given) with acceleration as g assuming that the experimental data allowed for it.

[Nov1mom]

If we are given Displacement s = ut + (1/2)(at

Edited June 28, 2008 by Nov1mom

[Macross1]

OMG, I'm not even reading this.

[Ultramega]

Come on, don't be so mean.

 

Even lawyers, doctors and professors with PhDs also hit the books for answers. CEOs, CFOs and Directors also consult people. Even our Prime Minister also do that lor. And they do that all the time.

 

It is ok to ask questions as long as the final objective is met. In this case the knowledge she gained here can be transfered to her students. Objective still met.

 

Are u in the work force? Have u not asked someone for help with work? Not even once?

 

[Maxus-MIFA9]

 

 

I even found such questions asked in this forum is

 

cos I will copied down and let my children solved it....... so it does help and I say......

 

 

..................KEEP POSTING MATHS QUESTIONS................

 

 

[Maxus-MIFA9]

Look my friend.....

 

some members here have school going age children and sometimes along the line, it does help one another by posting maths questions here.

 

What if one day your children came to you with a math problem and u get struck with it....., where will u go.....

 

Maybe, u are young and single, wait till u settle down and have children and u will understand if they are taking their, PSLE or GCE 'O' / 'A' or even currently on course at NIE to become a teacher.....

 

Learning doesn't stop when u leave school. I have not come accross this question in my school days and I find it very interesting reading it to widen my knowledge.

 

 

Cheers ....

[Ultramega]

Learning doesn't stop when u leave school.

 

This is the right attitude.

 

We learn from one another. Nobody in this world knows everything.

[Gearoil]

If we are given Displacement s = ut + (1/2)(at

[Nov1mom]

well, actually, think abt it this way:

if you are a parent, and you can say from the bottom of your heart that you would hire and pay a tutor who doesn't really know the concepts and needs help by coming into an internet forum, to teach your kid sitting for an exam, then i have nothing to say.

 

mind u, if you remember or carry out a search, it's not once or twice lor...

 

if u dun mind the above, do hire me to teach your child maths. my math so so but i took 'o' level maths and i can always come to mcf whenever i can't answer his/her qns. i only charge you $50 per hour, for answers which are not mine and which i probably cannot explain thoroughly anyway.

 

I'm sure you know the difference betw supplying an answer and explaining an answer.

[Nov1mom]

hi there, i do agree that it may be useful to post questions, maybe a separate thread can be created for that purpose, to share interesting / ridiculously difficult questions for different levels. then the students can do the questions and seek their teachers in school for help in checking the answers. that's a different thing altogether. my main concern is that students are not given proper explanation due to lack of conceptual understanding. if they need help, we should not try to help beyond our means, but direct them to the right people (school teachers) who are best able to teach and clarify these concepts for them. if for some reason, school teachers are not the preferred choice, then hire a tutor, but tutors should have the integrity not to teach when they are not capable enough.

 

my issue is that once or twice to ask questions is still within reasonable limits, because we dunno everything. but it's disturbing that it has happened more than once or twice. would you feel comfortable with such a tutor around?

 

if we were to perpetuate this, what is to become of our kids, our dear children?

 

---

 

by the way, i am a mother and also an NIE trained teacher. I have seen so many kids come to me confused by their tutors and I needed to sort them out. They had to unlearn and relearn, in the end they are slower than their peers without a tutor.

 

As parents, we always want the best for our children, and that is why I feel so strongly about this.

[Ultramega]

ok nice replies but u didnt answer my question. have u not even once asked anyone for any type of help with work?

 

If u haven't, i clap for u.

 

But next time when u have the need to seek help, pls don't ask for help. Instead, you should quit your teaching job immediately as you said, "tutors should have the integrity not to teach when they are not capable enough"...same goes to school teachers i suppose. Hope you practice what you preach. Ready to do that? Steady bo?

 

Remember what you have said here.

 

Cheers.

[Kenneve888]

Noted your point, though I would like to be easy on such issues. After all, this is a public forum, anyone can ask anything under the sun. If we do not feel like entertaining such question, just let it be. It will die of natural death. So relax lah.

 

Btw, did the thread starter say he is a "tutor"?

[Requiemdk]

Actually I think what she was trying to say was that asking once or twice for help on things like this is acceptable, but the TS has done this on several occasions which she probably feels is beyond what a normal tutor should be doing if he/she is to be proficient in teaching the subject. As teachers, we are fully expected to have mastered the content of the subjects that we teach. Asking for help on work that isn't about content is quite different from asking for help about the content itself.

 

But that said, the TS never said she was a tutor. Until I see otherwise, I'm more inclined to give her the benefit of the doubt, that she's a caring mom who genuinely wants to help her kids with their schoolwork but for some reason doesn't want to, or cannot hire a tutor, especially since tutors charge close to criminal fees these days for what amounts to basic academic education, and some don't even do a good job in the first place. I too have met more than my fair share of students who came thoroughly confused by their tutors and had to unlearn and relearn the right things. Personally, I have very strong feelings against the idea of tuition - it wrecks the whole idea of equality of education (gives the rich an almost insurmountable advantage) and is gradually turning self-discipline and independent learning into some sort of long forgotten art.

 

On the other hand, the internet was built on the premise of the sharing of information and knowledge. Let's not forget that. Academics all over the world exchange ideas and collaborate in research through it. What's the difference from attending to someone in need of some arithmetical help? I'd rather students be able to freely ask their questions on the net and get proper answers and explanations from qualified, and current, teachers than pay through their noses for dubious or unneeded tutoring.