Projectile motion (part 9)

[Kricardose]

I am very happy to see the vidoe Another example of projectile motion.after you give this

[bebeheuy]

I Love The Video Another example of projectile motion It Can Increase My Knowledge

[Mjhond]

Steady I Really Like This Video Another example of projectile motion

[safetybearry]

i guess the one dislike was b/c someone misunderstood his video and bombed a test...

[virtuosoikingpin]

I almost cried laughing when you said...."My trusty calculator provided by windows", and just pulled it out.. xD

[cheese0cake]

i got 1 question

for example you throw a ball up at 10m/s

at t=0, is v=0m/s (snce motion hasn't started yet

or v = 10m/ss

[Stratocaster1111]

@cheese0cake it's 10m/ss the moment it leaves your hand.

[leadershipcouncil]

How fast did I throw up? LOLLL

[achtpanz88]

I have a question: In a projectile motion (one motion), does the time for the object to travel from the starting point (y*0=0) to the highest point equal to the time for the object to travel from that highest point to the end y=0?

[mansur123]

@achtpanz88 Yes it does.

[hollyflowerrose]

I understand why final velocity is zero, but it always seems to me that initial velocity would also be zero, because the ball has not been thrown yet. What am I missing here?

[Exildeutscher]

thats because you have to throw against the pull of gravity. so basically you throw it at x m/s UP, which is your initial velocity, at the half-way mark, the velocity changes to x m/s DOWN, or -x m/s UP. From there on, the velocities start to cancel each other out, leaving you with 0.

[RichardJordan100]

ball throwing

[gklrajan]

gr8! i tried to solve it the other way i.e. by taking vi=0 nd taking vf=unknown nd i got the same answer 35m/s... thankyou! for giving such a gud aproach 2 dis prblm cuz wat v usually do is mug up the formulae nd aplly it but this is really get! after watchin ur videoes i started appretiating phy but nyway its too late nw.. i'm alredy prep 4 medical!! thanks a lot sal!

[RodimusX]

thanks so much for posting all these wonderful videos! they really do help me out a lot. i have always loved physics until this year where i had such a difficult time keeping up. i really wanted to enjoy it again so you are definitely being a real big help. i appreciate it. :)

[NewMnT]

Your vids r real helpful. Thankx for uploading.

[Evidenced]

He solved the problem without resorting to formulas. Since you knew the t = 3.5 secs and g = -10m/s^2... you know that v_i must be 35 because 35 - (1)10 - (1)10 - (1)10 - (1/2)10 = 0. Now that you have v_i and v_f, you just average the two and plug it in d = (v_a)(t). (you can average them simply because the velocity is linear and the acceleration is constant).

[bkjoelover]

why cant we use the distance= (vf2-vi2)/2a?