# Homework Help: New to physics - throw me a bone here

1. Jan 29, 2005

### Grandor

I have just started Senior physics at high school and am relitavely new to physics.
I am unsure if I wish to pursue physics as a career or not.

Can someone post some starting points? Some sites to go thru step-by-step and teach physics?

2. Jan 29, 2005

### ShawnD

Don't you need 1 or 2 previous physics classes before you can take senior physics?

Physics, like chemistry, is basically just trying to cancel out units. If you have velocity (m/s), frequency (1/s), and wavelength (m), it's fairly obvious that multiplying frequency and wavelength will result in velocity since the units work out properly.
It only starts to get tricky when the unit difference between the formula you want and the formula you have is a unit your known formula has (if this sentence makes no sense, just keep reading on). Example, momentum is P = mv which has the units kgm/s. Now say I want to get kinetic energy based on that formula, the units I'm trying to get to are kgm^2/s^2, basically a unit difference of just velocity v which is m/s. I can't just multiply my momentum formula to get E=mv^2; I need to integrate it with v.
$$E = \int mv \,dv = \frac{1}{2} mv^2$$
Another example is going from velocity to distance. Velocity is v = at. To get distance from velocity, you usually just multiply by time, but the formula we start with already has a time component, so it has to be integrated.
$$d = \int at \,dt = \frac{1}{2}at^2$$

It's a lot easier to understand if you take calculus first.

Last edited: Jan 29, 2005
3. Jan 29, 2005

### FulhamFan3

ShawnD:

Your post makes no sense. Also my high school had only one physics class so it's understandable he's starting his senior year.

Grandor:
If your goal in a physics career is to teach than that's great. They are always looking for physics teachers so you would almost be guarantee a job. I beileve most physicists work in research in academia. Depending on what discipline you want it might be better to do engineering when it comes to the private sector.

Basically physics has alot of math in it. If you hate math then you should look for something else.

4. Jan 29, 2005

### ShawnD

It makes sense if you understand highschool calculus.

5. Jan 29, 2005

### FulhamFan3

I understand the equations you have no problem. It's your statement that physics is basically cancelling out units that I don't like.

I did have a Physical Science class which was somewhat of an intro to physics, chemistry and biology. But we only had one class that was purely physics.

Last edited: Jan 29, 2005
6. Jan 29, 2005

### Grandor

Oh sorry, I am in Australia and have just come from year 10 into year 11.
Year 11 and Year 12 is ONE course here (hence senior physics).
I have done 'science' up until now, which was mandatory (there were no elective sciences either).

I am fairly good at maths, except there was a really bad teacher for the last two years that I've had and I didnt quite get some of the things he taught.
I got 7th out of 20 students in the Highest Maths class (out of 3 (advanced, intermediate, and standard), it was a small school).
In my Year 10 School Certificate (state-wide exam) I got a mark of 89 in Science. Also I have a High Distinction in Chemistry from an International Competition run by a university here.

I like Physics, I dislike Chemistry, I enjoy problem solving mathematics, I dislike learning maths that I wont ever use (gradient formula's and such)...

7. Jan 29, 2005

### beth314159

ShawnD's response that "physics is just cancelling units'" is like saying that writing a book is "just typing on a keyboard". Sure, when you perform a calculation to solve a physics problem, you may cancel units. But physics is not about plugging through problems in a book. Granted, one's physics eduacation begins with textbook exercises, but when you learn physics, you are really learning a _skill_ with which you can tackle an enormous variety of real-world problems. Any career path which requires a science background will reward a physics education. You can always choose your career later, but you need to get the education now. Take physics, its fabulous!

-Beth

8. Jan 29, 2005

### Grandor

Jobs on the cards:
- Medical Doctor.
- Musician.

Yeah they are very different, But I will probably end up doing both.

9. Jan 30, 2005

### FulhamFan3

sounds like you would like a physics/engineering. As for learning math you won't use. Depending how deep you go into physics, any math you learn WILL be used in physics. Especially the gradient formula.

10. Jan 30, 2005

### buddingscientist

Grandor, are you in NSW?
Like you say you have taken up to year 10 science, as have all the other students. Howso are you relatively new to physics when everyone else in your grade (and year 11's in the state) are on the same footing as you ?

If you are unsure as to persue a career in phys or not, surely wait until you complete yr 12 ?
For starting points your textbook, the bos syllabus (if you are indeed in NSW)

11. Jan 30, 2005

### Grandor

Yeah im in NSW.
Yes im on the same boat as everyone else.
However, I would just like to get ahead. I'm a global learner, and I think if I get alot of the other physics concepts It will help me absorb more in class.
I am aiming for a UAI of >90, so i am keeping my options open. But at the moment I'm thinking I'll do B.Med/B.Surgery

12. Feb 1, 2005

### buddingscientist

fair enough then (from NSW here too)

for med you'll probably need minimum 95 uai, very good umat percentiles and an excellent interview (for eastern aus unis)