ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Physics => Topic started by: ghadz7 on June 07, 2010, 02:48:06 pm
-
What happens if you take g as -10 m/s^2? Do you lose marks?
-
Don't take my word but I think you can, if you specify what direction the positive is. Someone kindly clarify this for me please.
-
y would u lose marks for that? As long as it fits into the context of the question then its fine.
-
I presume you mean rather then 9.8m.sec^2 - it actually says on the cover page which you can download on the VCAA website it says "You should take the value of g to be 10 m s–2"
as to whether it's positive or not depends on what you define as positive. eg. accelleration of vertical motion for projectile motion should be -10m.s-2 as the force is acting downwards.
-
as to whether it's positive or not depends on what you define as positive. eg. accelleration of vertical motion for projectile motion should be -10m.s-2 as the force is acting downwards.
I don't think it matters either way. as long as your answer is logical. Ie you don't have negative time!
Basically, just draw a little diagram that says Which way you are assigning positive.
-
as to whether it's positive or not depends on what you define as positive. eg. accelleration of vertical motion for projectile motion should be -10m.s-2 as the force is acting downwards.
I don't think it matters either way. as long as your answer is logical. Ie you don't have negative time!
Basically, just draw a little diagram that says Which way you are assigning positive.
Yes. I agree with this.
-
I presume you mean rather then 9.8m.sec^2 - it actually says on the cover page which you can download on the VCAA website it says "You should take the value of g to be 10 m s–2"
as to whether it's positive or not depends on what you define as positive. eg. accelleration of vertical motion for projectile motion should be -10m.s-2 as the force is acting downwards.
You can use 9.8 or 10, they won't deduct marks for that. Don't see why you would choose to use 9.8, though.
-
yeah just check the cover page, they should tell you what value of g to use.
-
You have to use 10, but the direction is my concern.
-
you dont HAVE to use 10...but why wouldnt you?
-
You have to use 10, but the direction is my concern.
oh i was gonna mention direction from ur first post but i thought u knew about it
anyways its just definitions, define ur + and -, shud be fine.
-
You have to use 10, but the direction is my concern.
If the projectile is launched with a velocity that has an upwards component, I don't see how you can avoid using g = -10m/s^2
-
You have to use 10, but the direction is my concern.
Did you read my post? You don't, but you should.
As long as you don't answer a question with negative as the direction (state specifically), it'll be fine (of course, assuming your working out is logical as well).
-
You could define upwards as negative if you're the kind of person that likes to complicate stuff on themselves (my teacher).
-
You could define upwards as negative if you're the kind of person that likes to complicate stuff on themselves (my teacher).
nope, setting up as negative is not always complication, it depends on the number of vectors pointing up, if more vectors are pointing down than down, defining negative as up would be a simplification as u have to deal with negatives less