CSSA MX1 Discussion Thread (1 Viewer)

[xbejo]

Guys the projectile motion multiple choice, about the 3 balls dropping, do you think that was a fair maths question or was it more inclined for physics? I think it was unfair for people who dont do physics

If you quickly developed the vertical equations of motion, you would see that they would all be the same.
(order may be wrong)
For scenario A (no horizontal velocity), we have y(doubledot) = -g, y(dot) = -gt and y = -gt^2 / 2 <----- since the angle of projection is essentially 0, Vsina = 0 (for any V, Vsin(0) is always 0)
For scenario B (10m/s i believe), we have the same thing
For scenario C (15m/s) we also have the same thing.

I myself put down 15m/s, it was not until after the exam i noticed my mistake.

 

[rickster]

Did you guys managed to get the MI in Q 14 a?
I couldn't factorise a 6 out

You were supposed to take the 6 out and leave a 0.5 inside the bracket. Within the bracket, there was a (k+1)(k). That multiplied by the 0.5 is always a whole number since for k>1 or k=1 (k+1)(k) is always even. You could have just stated that or could have used induction again to prove that it was even.

 

[rickster]

If you quickly developed the vertical equations of motion, you would see that they would all be the same.
(order may be wrong)
For scenario A (no horizontal velocity), we have y(doubledot) = -g, y(dot) = -gt and y = -gt^2 / 2 <----- since the angle of projection is essentially 0, Vsina = 0 (for any V, Vsin(0) is always 0)
For scenario B (10m/s i believe), we have the same thing
For scenario C (15m/s) we also have the same thing.

I myself put down 15m/s, it was not until after the exam i noticed my mistake.

Yeah pretty much. I thought it was funny that they reduced projectile motion to a multiple choice question. It seems like a really popular thing to do since a lot of 2012 trials have a projectile motion question as a m/c.