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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Specialist Mathematics => Topic started by: jimmy999 on August 28, 2009, 05:31:26 pm

Title: What's the best way to approach dynamics/mechanics questions?
Post by: jimmy999 on August 28, 2009, 05:31:26 pm: So far this year I've averaged full marks in all of my sacs and I've gone through a whole bunch of practice exams already.

What I've noticed is that I can easily tackle most questions, but where I usually lose marks is in the dynamics/mechanics area. It's usually only 1 or 2 marks but it's the few marks I don't want to lose

So what I want to know is how people approach these type of problems. I don't do physics and at the moment we are halfway through the chapter in class so I'm still refining my skills but what do people think is the best way?
Title: Re: What's the best way to approach dynamics/mechanics questions?
Post by: /0 on August 28, 2009, 06:25:45 pm: If you really want to be sure you're not going to lose any marks then draw free-body diagrams. In your diagram, include all forces acting on each particle. A picture is worth a thousand words.
There have been times where I have simply assumed that $\mu mg \cos{\theta}$ will give the frictional force, but in inclined plane problems this isn't always the case, so it's best to derive the friction force step-by-step by first finding the normal force.
Also, with nearly every motion problem, designate a positive direction and write it down so you don't forget it.
Title: Re: What's the best way to approach dynamics/mechanics questions?
Post by: TrueTears on August 28, 2009, 06:28:59 pm: I usually go through 3 simple steps.

1. Draw all forces acting on the object.
2. Designate positive and negative direction.
3. Resolve forces parallel to plane and perpendicular to plane.

Always works.
Title: Re: What's the best way to approach dynamics/mechanics questions?
Post by: kamil9876 on August 28, 2009, 06:44:24 pm: http://en.wikipedia.org/wiki/Philosophi%C3%A6_Naturalis_Principia_Mathematica
Title: Re: What's the best way to approach dynamics/mechanics questions?
Post by: NE2000 on August 28, 2009, 08:31:01 pm: Also in addition be very clear about what you're trying to do before you start, although you probably already do this given your high marks, but if you know this then the next step is quick diagram and the rest should be fairly basic.

It's also a lot easier if you do physics :P
Title: Re: What's the best way to approach dynamics/mechanics questions?
Post by: Mao on August 29, 2009, 06:46:08 pm: Quote from: TrueTears on August 28, 2009, 06:28:59 pm
I usually go through 3 simple steps.

1. Draw all forces acting on the object.
2. Designate positive and negative direction.
3. Resolve forces parallel to plane and perpendicular to plane.

Always works.

^^ well said

that is THE fool-proof way. Has never failed, will never fail :)
Title: Re: What's the best way to approach dynamics/mechanics questions?
Post by: sachinmachin on September 02, 2009, 03:47:54 pm: Quote
Quote from: TrueTears on August 28, 2009, 06:28:59 PM
I usually go through 3 simple steps.

1. Draw all forces acting on the object.
2. Designate positive and negative direction.
3. Resolve forces parallel to plane and perpendicular to plane.

Always works.

^^ well said

that is THE fool-proof way. Has never failed, will never fail Smiley

couldnt agree more