Can we use 3u maths to do Projectile questions? (1 Viewer)

[rsingh]

So are we allowed to use 3u rules/concepts to do Projectile motions?

Like in last yr's paper, the first short-answer question was based on projectile motion and was worth 4 marks. It asked to find the range.
But if we use 3u, that'll probably just take 2-3 lines, recalling a formula, substituing values and finding the answer.
So would we be awarded the full 4 marks if we did that? Or must we use the proper physics formulas?

 

[Captain Gh3y]

Yes. Yes we can.

 

[KFunk]

You're safer using the ones they provide, they're the same ones anyway. For example, max range is found when y = 0.

0 = u_yt - (g/2)t² = Vsin@t - (g/2)t² so t_max = 2Vsin@/g

x = u_xt = Vcos@t

Therefore max range = V²sin(2@)/g = whatever

Same deal as 3 unit eq'ns just safer and without the need to derive.

 

[rsingh]

ok thanks for that.

 

[Raginsheep]

So are we allowed to use 3u rules/concepts to do Projectile motions?

Like in last yr's paper, the first short-answer question was based on projectile motion and was worth 4 marks. It asked to find the range.
But if we use 3u, that'll probably just take 2-3 lines, recalling a formula, substituing values and finding the answer.
So would we be awarded the full 4 marks if we did that? Or must we use the proper physics formulas?

But remember, in 3u, you are required to derive all projectile motion formulas unless specifically stated. If you were to derive such equations, it probably be acceptable. Quoting them maybe not.