Ok, well, I'm not in AP physics, I'm in honors, but even so I need help.

In our class we are trying to get find the KE and GPE of a rubber ball (those rubber balls that's like 25 cents)

GPE = Mass x Gravity x Height

KE = 1/2 x Mass x Velocity^2

The givens were the Height, the Gravitational Pullt (we're just going to round 9.8 to 10 m/s) and the mass is 0.0235kg.

So the GPE is the one we found out pretty easily, but the KE is the tricky one mainly because of the Velocity. I should probably tell you we are dropping the ball from a free fall so we don't need a timer, however, we need to find the time to get the velocity, so we need to use the Free Fall equation in order to get that.

aaaannnd. that's where i'm stuck at. I can't seem to get the time.

wouldn't the equation be:

Dy = 1/2gt ?

and KE would be

KE = 1/2m(gt)^2?

so to get the time it would be:

(going back to the Dy equation)

t = [(1/2)g]/Dy

Since the Dy is the Height.

right?

Thanks in advance.

capitalization? who the heck came up with this horrible rule?!

[IMG]http://i40.photobucket.com/albums/e201/Ohnn/ID.jpg[/IMG]

[=DarkOrange][=2]my ap equilavent courses:

ib art; ib math sl; ib english

Ok, so let's say A is delta and E is sum

EAMechEnerg=AKE+APotEnerGrav-W+F.L.+APotEnerElastic

so 0=(KEf-KEi)+(PEgf-PEgi) right?

if it's dropped from rest then KEi=0

the PEgf would be 0 as well right?

KEf=1/2*m*V^2

-PEgi=m*g*hi

so KEf=PEgi

1/2mV^2=mghI

what's the displacement? (h)

does that help at all?

I tried :)

I take

AP US 2

Honors Physics

Honors Precalc/Trig

and still can't figure out

how I manage to pass.

???

yea. it did.

thanks!

^^

and a got a 90 on the lab report, so I'm happy. :D

Thanks again.

capitalization? who the heck came up with this horrible rule?!

[IMG]http://i40.photobucket.com/albums/e201/Ohnn/ID.jpg[/IMG]

[=DarkOrange][=2]my ap equilavent courses:

ib art; ib math sl; ib english

oh, great!

no problem:)

just glad to help

I take

AP US 2

Honors Physics

Honors Precalc/Trig

and still can't figure out

how I manage to pass.

???