How can I improve my physics skills for my upcoming exams?

[ZGMF - X20A]

I'm really sorry if it's not in the correct place. I just want to know how you guys study physics so well. I'm in Secondary 3 (ninth grade) and my exams are coming in like..1 week lol. Recently I've been learning about force, energy, power, pressure, speed, velocity, heat capacity and specific heat capacity, latent heat of fusion/vaporization and specific latent heat of fusion/vaporization. Well, I almost NEVER do well in any topics. I can't say that my teacher's lousy, but she keeps telling me to study by myself. I find it somehow hard because textbook only gives me equations and solutions to easy questions. I've got the Ten-Year-Series which includes papers from ten years of O levels. Well, questions are definitely not that easy and there are solutions to them, but I just don't seem to understand everything it says. Can anyone help me here? I would appreciate it if you can show me any websites/anything that helps me improve my physics skills. Thanks.

 

[Poop-Loops]

Yeah, I know what you mean. The book only gives answers to completely obvious problems, but the homework is a lot harder.

My advice is to ask her how to study better. If she says "just do it by yourself" or something that doesn't help, then you can safely say she is a lousy teacher. My physics profs have all said to work in groups, but to have everyone do the problem themselves (so no copying, obviously).

Best advice given to me for solving physics problems: look at the big picture first. What are you trying to find? Then use the most basic equation you get, and go from there. So if you need to find some sort of force, immediately start with F = MA and go from there.

 

[ZGMF - X20A]

Thanks, I'll try that.
And it's not that my teacher doesn't solve the questions for me. It's just that her lessons are SO boring that 4/5th of the class gets sleepy everytime and I don't really understand it when she solves equations.
Ask her how to study better? I didn't even need to say anything and she already told me to do online stuff on our school's online learning management system. There are questions and solutions together with explanations up there, but what's the point when questions are taken off from the ten-year-series. It didn't really help much.
Sometimes before tests there would be sheets of difficult questions and answers. She tells us to study them and most of them would come out (probably all) for the tests. So what's the use of studying them when we don't even understand them and we can just memorize to earn marks?
I seriously don't know how to study better other than that. I do organize group studies with my friends, but somehow the questions we solve are limited and I still can't absorb much. Help anyone? Thanks.
Oh yeah, I would really appreciate it if someone can give me lessons on tension, (specific) heat capacity, (specific) latent heat, pressure. Thanks a bunch.

Edit: Ok this is a problem I don't understand.
https://www.physicsforums.com/showthread.php?p=1093766#post1093766
All I thought of was just take the mass and acceleration given to find force.

 

[Poop-Loops]

Everything you just told me, tell her.

 

[oksanav]

I only get bored during lectures when I'm lost, or zone out. I avoid this by asking questions, even if it's just confirming the principle behind his solution "so you did this and this ". For problems, working in groups of 3 (any more tends to turn social) can be very productive. Drawing a picture and writing down some likely equations is the best way to start the problem for me.

 

[ZGMF - X20A]

I tried doing that. Pictures don't really help me. They just kinda tell me what happens in the question. The problem is how to get to the answer. Writing down equations? I've never tried that though. I just jump straight into working xD. Thanks, I'll try that. Hope it works.

Everything you just told me, tell her.

I'm afraid she has been told by my friends a few times already. The weird thing is, some of her students actually get distinctions in O levels.

 

[Poop-Loops]

Never just jump straight into it. Especially if you ever do any programming. :p

Look at the big picture. What are you supposed to find? Then take the most basic formula you can find in order to end with that unit. So if you need to find a, it might be a = F/m or a = d/s^2, depending on what else is given. If it turns out you picked the wrong equation, then start over. That was just a shot in the dark.

I remember one time we had a mid term where people did generally bad (not me, though, I was considered one of the Three Physics Gods in the class :D). People complained that there wasn't enough time (2 hours). So the professor said "ok, let's solve this test now" and did it in like 30 or 40 minutes, with full explanation. It's because he knew how to solve the problem. It suddenly became easy. But he never jumped into it, he always took a step back and looked at what needs to be solved first, and took steps to get there.

 

[ZGMF - X20A]

^ Thanks for the reply. There's a problem, sometimes I don't understand why they take this and that steps. You see, in heat capactity and latent heat, there's this equation:
E= mc(deltatheta) + ml.
Though I don't know why it contains both ml and mcdeltatheta. Explanations please? Thanks.

 

[Sojourner01]

Me neither. I've never seen that form before.

Ask.

 

[ZGMF - X20A]

It's like when there's an ice cube on the surface of a glass of water. After a while, there will be water around the cube loses temperature and becomes ice. And that's the equation for finding the energy used.
And can someone give me ninth-grade/O level difficulty questions on specific heat capacity and latent heat of fusion/evaporization together with showing how you arrived at the answer. Like, you guys tend to write down equations related to the answer/question. So can anyone here show me step by step what exactly you guys did including writing down equations to arriving at the answer. This would be REALLY REALLY REALLY appreciated if anyone can help me. Thanks again.
Oh yeah, sorry for asking too much but I really need to know. How is potential enerygy (mgh) related to kinetic energy (1/2mv^2). I can't really realize when mgh=1/2mv^2 as a guy goes down a slope and when mgh=/=1/2mv^2 as another guy goes down another slope. It seems like the difference lies in the slopes. Or when he still continues to go down at one point and when he stops heading down at another point. And also the loss in kinetic energy.Here's one question.
The stone has mass 0.23kg and leaves the thrower's hand at t = 0. It hits the ground at t = 0.325s and rebounds with 50% of the speed with which it hit the ground.

(Graph:
When t = 0, m/s = 2
When t = 0.32, m/s = 5.2
From t = 0 to t = 0.32 it's a straight line so the stone is traveling at a constant acceleration.
At t = 0.325, the stone's speed is 0m/s and rebounds with half the speed which it hits the ground (i.e 50% of 5.2m/s = 2.6m/s)

(a) Maximum speed = 5.2 m/s
(b) Show that the acceleration of free fall is 10m/s^2.
a = (v-u)/t
a = (5.2 - 2)/ 0.325
a = 9.8 = 10 m/s^2 (proven).
(c) Determine the speed of the stone just after it rebounds.
Speed = 2.6m/s (obviously)
(d) Calculate the loss of kinetic energy of the stone as it hits the ground and rebounds.
I didn't know how to do this question.
I just know that the formula is 1/2 x m x v^2.
So I went:
0.5 x 0.23 x 2.6^2 = WRONG.
It's actually:
0.5 x 0.23 x (5.2 - 2.6)^2 = WHY 5.2 - 2.6?

Thanks.

 

[bkvitha]

Have you tried getting any revision books!?
Get those at your level which explain a bit more briefly for your syllybus but not too much.

It does help(cause I am at your level too).

If you cannot obtain one. Let me know.If you really can't get help from your teacher, ask help from top physics students in your class. they might help. Anyway use flash cards stating all the necessary formulae.

I think they meant...

E=mc(theta)=mL only when the problem involves both an increase or decrease in temperature, and a change in stateof the substancw...(correct me if I'm wrong---cause i just saw this in my revision book----exams next week =< )

 

[ZGMF - X20A]

I got the ten year series for O levels (examination papers in the past 10 years).
It kinda helps. I tried asking my teacher about the heat capacity and latent heat thing and what do you know, I have a better understanding of it! LOL though my teacher doesn't have that much free time. I need one more explanation please: when does mgh = 1/2mv^2?

 

[ZapperZ]

You should not be using this forum to ask homework/schoolwork type questions. Please create an appropriate thread in the Homework forum.

Zz.