gohby SG FYI, I drew a straight line. I understand what u mean by "cannot find gradient" cos I thought the same way too. As a result, I was not very convinced with my teachers' answers. But anyway, ALL (my teachers) say its a curve. A very slight curve. And yes, I really dont wish to talk about the physics practical. Its deceptively simple. >_<
Orange*Asterisk SG i got a curve too. i cheated. i calculated the difference of the time interval btw every 5 cm and ploted the graph :p
Classyfied SG it should be a straight line...best fit straight line... or else they will nt ask u calculate the gradient.. this year the examiners very fukker..never say draw wad type of curve shape... my teacher even confirmed with me that it is a str line. =) so cheers actually ytd one not that hard la... except one question.... wad did u all say abt the image? is it diminished or same size or enlarged? i wrote same size leh... haiz.
Orange*Asterisk SG it's a curve. since acc of free fall is at constant, integrate a constant graph will eventually get u a curve.
vice_edge SG i plotted a best fit straight line . mirror question was a pain in the ass screw physics la
vice_edge SG i plotted a best fit straight line . mirror question was a pain in the ass screw physics la the teaches also nv see the paper how to confirm curve or straght line la
TwinTurbo_Supra SG theoratically it's a curve, because the marble reaches terminal velocity. but u think the marble can reach terminal velocity within 90 cm?
Classyfied SG cannot 90 cm... they give u the cloth cover the ruler one.... all drop from the same length of 80cm...
vice_edge SG range was 20cm- 75 cm for me . needle one i screw for method 1 focal length.. plus how to integrate? ppl who dun take amaths die la
Classyfied SG is all drop form 80 cm right.??? then u use the cloth move up to get different lenght right? dam i screwed it up... i drop the marble at different spot... at 70 cm.60 cm 50 cm... dam...... and also my curve i draw str line... dam...... and also wad is the size ofd the image formed? magnified or same size?
vice_edge SG my range was 20,30,40,50,70,75 .. i got straight line . i put smaller image and focal length gone case i got 1cm… method 2 was 18.5+20 divide by 2
Classyfied SG but my freind say is all roll from the same point of 80 cm…then use the cloth cover parts of the ruler to get a different reading…?? dam i m screwed
vice_edge SG the question got say about 40 cm for range annot ? anyway my school give me curve ruler no cloth to catch the goli marble
and i name it recorded times/no., wtf. 
