2004 hsc question 16 answer thanks :) (basic projectile motion) just want to check (1 Viewer)

[RishBonjour]

Question 16 (4 marks)
A projectile is fired at a velocity of 50 m s–1 at an angle of 30° to the horizontal.
Determine the range of the projectile.

 

[clementc]

Re: 2004 hsc question 16 answer thanks (basic projectile motion) just want to chec

220.9248m?

Stupid Board of Studies always harps on about people not having correct sig figs, but doesn't seem to know sig figs themselves. You would have to guess if they want 1 or 2, because the noobs never make it clear whether they want to count 30 as having 1 or 2 SF.

After getting smashed in school for assuming 30 was 1SF (which it can be), I guess you always assume the highest number of sig figs, so say 2 for this example.

So just say 220.9248 (etc full calc display) = 220m.
Though in the same way you assumed 30 was 2SF, then 220 is now 3SF, but nvm =(

 

[Fizzy_Cyst]

Re: 2004 hsc question 16 answer thanks (basic projectile motion) just want to chec

sig figs dont matter in physics, only chem

 

[Bobbo1]

Re: 2004 hsc question 16 answer thanks (basic projectile motion) just want to chec

are we allowed to use that formula in physics, considering its not on the formulae sheet?

 

[taeyang]

Re: 2004 hsc question 16 answer thanks (basic projectile motion) just want to chec

are we allowed to use that formula in physics, considering its not on the formulae sheet?

Yes you are allowed to use it.

 

[clementc]

Re: 2004 hsc question 16 answer thanks (basic projectile motion) just want to chec

Personally I really doubt you can, but everyone keeps saying you can. Ultimately with the risk of losing the 3-4 marks normally given for questions like those, I wouldn't chance it T__T
Also you always have heaps of time for the science exams, so it can't hurt to do it the normal way =D

 

[Fizzy_Cyst]

Re: 2004 hsc question 16 answer thanks (basic projectile motion) just want to chec

are we allowed to use that formula in physics, considering its not on the formulae sheet?

The equation for orbital velocity or escape velocity aren't in the formula sheet either, but you definitely use them!

I have talked to HSC markers, and they say you can use Maths in Physics, which kinda make sense if you ask me

It is all just deriving from stuff which is in the formula sheet anyway





By factoring, t = 0 or

 

[clementc]

Re: 2004 hsc question 16 answer thanks (basic projectile motion) just want to chec

Yeahhh like you can use them but you still have to derive them, not just quote the formula from nowhere. That's why there's a data sheet, so you know what you can quote and not.
It's just like with orbital/escape velocity >=0 You still have to derive them by equating centripetal = grav. force/by conservation of energy.

 

[Chicken Wang]

Re: 2004 hsc question 16 answer thanks (basic projectile motion) just want to chec

Using formula's from the syllabus I found y range through final velocity^2 - initial velocity^2 / 2xg = 127.5m. Then x range = horizontal component x time of flight.. which came to 10.2 seconds.. Ending up with 440m for x range.. Where did i fuck up ahah??