projectile motion (1 Viewer)

[bouncing]

hey guys,

didn't listen properly in class
cannot even understand this proof .....

HELP D:

for horizontal motion...


etc etc

BUT WHERE DOES THAT "t" come from??! when you integrate Vcos(theta)??

edit: oops sorry about crappy latex typing ><

 

[b00m]

well.. i haven't learnt this yet, but by comprehending basic integration concepts..
when you integrate something to "dt"

you add an extra power of 't'

for eg.. integrate: (3.dt)

= 3t + C

or integrate 6t^2.dt

(6t^3)/3 + C = 2t^3 + C

 

[bouncing]

yeah thats what i thought but like when you integrate cos theta dont you get sin theta???

 

[philly2000]

no like boom said you're integrating with respect to t, hence the 'dt'
so t is the variable in this case not theta

 

[bouncing]

so you're treating vCos theta as just a number right? ..... i think i get it
thanks for the help guys - appreciated!!

 

[b00m]

so you're treating vCos theta as just a number right? ..... i think i get it
thanks for the help guys - appreciated!!

well as i said, i haven't learnt the topic yet.. but i think 'vCos theta' is a constant.. as it says it's equal to "C" (constant)

 

[bouncing]

yea yeah.. got it (Y)

its cos there is no acceleration acting on horizontal motion since we only take into account of gravity which only affects vertitcal

thanks guys