Help for projectile please!! (1 Viewer)

[supermike]

hi! i had trouble understanding projectile quesitions that ask u to find the velocity of projeciton. i know the pythagoras' theorem thing usually works ...
(v dot square= x dot square + y dot square ) sry for the bad reprsentation X)
now we know there is "t" in y dot while x dot is a constant, so id like to know wat value of "t" we should substitute into the equation!!
i seen a lot of examples dat just sub in 0, but sometimes its some other numbers!!

"t" = time


thanks !!!!

 

[Thecorey0]

hi! i had trouble understanding projectile quesitions that ask u to find the velocity of projeciton. i know the pythagoras' theorem thing usually works ...
(v dot square= x dot square + y dot square ) sry for the bad reprsentation X)
now we know there is "t" in y dot while x dot is a constant, so id like to know wat value of "t" we should substitute into the equation!!
i seen a lot of examples dat just sub in 0, but sometimes its some other numbers!!

"t" = time


thanks !!!!

The velocity of the projectile is often not constant, therefore each value of t leads to different velocities. If you want the initial velocity, you sub in t=0, if you want the velocity 5 seconds after launch, you sub in t=5 etc. The value of t used depends on when the velocity you are after occurs.

 

[supermike]

The velocity of the projectile is often not constant, therefore each value of t leads to different velocities. If you want the initial velocity, you sub in t=0, if you want the velocity 5 seconds after launch, you sub in t=5 etc. The value of t used depends on when the velocity you are after occurs.

hey thanks Thecorey0!!! so i suppose it depends on the wording of the question if it simply asks for "velocity of projection"!?!?!?

thanks again XD

 

[untouchablecuz]

the velocity of projection is the velocity of the projectile when t=0

 

[supermike]

its a different interpretation from thecoreyo 's , but i think i get a fair idea wat to do with these questions now THANKS!!

 

[Thecorey0]

its a different interpretation from thecoreyo 's , but i think i get a fair idea wat to do with these questions now THANKS!!

Untouchablecuz is right, I misunderstood what you were trying to say.