Can somebody help me? Science Gravitational Acceleration

I'm the dumbest guy in Science [Razz]

b ut heey
I tried this.
when objects fall toward the earth they fall with an acceleration of 9.8m/s²

a = Acceleration
v = velocity
t = time

a = v2-v1
-------
t2-t1

So if i were to solve for v2
would it be like this ??
v2 = a(t2-t1) + v1 ?

Then I have A tennis player throws a ball upward at 15 m/s (v1) What is its veloctiy after 2.0s ?
v1 = 15m/s
t= 2.0s
a = -9.8 m/s (cuz it's going down)

(-9.8m/s²) (2.0s) + 15m/s
= -19.6m/s + 15m/s
= -4.6m/s

am i on the right track? I really don't know what i'm doing lmao.

Posted: Thu Nov 17, 2005 6:42 pm Post subject:

Posted: Thu Nov 17, 2005 6:54 pm Post subject:

okay thanks. This makes me feel a whole lot better haha Last time I had done like 30 of those problems but it was only acceleration & I thought i did them right but i didn't xD I think I did it right again.. but i was just making suer & yeah ty [Very Happy]

Posted: Sat Nov 19, 2005 7:56 pm Post subject:

u r right

Posted: Sat Nov 19, 2005 7:56 pm Post subject:

crongragulations!!!!!!

Posted: Wed Nov 23, 2005 6:29 pm Post subject:

yeah so my physics unit is over, thanks [Razz]

Posted: Wed Nov 23, 2005 7:30 pm Post subject:

JARGON! *hides behind the double-poster*

I suck with Physics formulae, so I couldn't of helped you when you needed the help x.x

Posted: Wed Nov 23, 2005 7:40 pm Post subject:

What are you starting now? Chemistry?

Posted: Thu Nov 24, 2005 8:09 am Post subject:

YES CHEMISTRY :'( is anyone good at that? lmao

Posted: Thu Nov 24, 2005 11:22 am Post subject:

Yeah I'm good at Chemistry =D

Balancing and all that is the hardest...

Posted: Thu Nov 24, 2005 2:59 pm Post subject:

the secret of chemistry.. everything wants to be stable.. lmao
well thanks I know a few chemistry peeps who can help me too

Posted: Thu Nov 24, 2005 6:43 pm Post subject:

Chemistry is fun! [Very Happy]

*pours two chemicals together and watches it fizz over the edge while carbon dioxide is flowing out of the tube*