To determine the height of a building a stone is dropped from the top of the building and into a lake. It takes 6.8 seconds for the stone to hit the water. What is the height of the building?





Blogs > dancefayedance!~ |
dancefayedance!~
396 Posts
To determine the height of a building a stone is dropped from the top of the building and into a lake. It takes 6.8 seconds for the stone to hit the water. What is the height of the building? ![]() ![]() ![]() ![]() ![]() | ||
![]()
Xeofreestyler
Belgium6771 Posts
Seeing how a = 9,81 m/s² which is the acceleration of the object You only have to put it in your formula and voila | ||
dancefayedance!~
396 Posts
| ||
ToT)SiLeNcE(
Germany590 Posts
| ||
HonkHonkBeep
China353 Posts
| ||
dancefayedance!~
396 Posts
| ||
ilovejonn
Canada2548 Posts
| ||
Eti307
Canada3442 Posts
On October 18 2007 04:52 dancefayedance!~ wrote: it's in a calculus book :/ It's still not calculus, this is basic physics | ||
dancefayedance!~
396 Posts
| ||
![]()
IntoTheWow
is awesome32275 Posts
| ||
randombum
United States2378 Posts
| ||
![]()
IntoTheWow
is awesome32275 Posts
![]() | ||
![]()
IntoTheWow
is awesome32275 Posts
| ||
azndsh
United States4447 Posts
v(t) = g*t, where g = 9.8 m/s^2 solve for h, such that integral from 0 to t_h of {v(t) dt} = h, where t_h is the time it takes to hit the water: 6.5s of course, the left side, you get integral from 0 to t_h of {g*t dt} = 1/2 g*t^2 evaluated from 0 to t_h = 1/2 g * (t_h)^2 So h = 1/2 * (9.8 m/s^2) *(6.5s)^2 | ||
![]()
Insane
United States4991 Posts
<hr> If you want to solve it in a calculus way consider it as a series of initial value integrations: Let p(t) be position, v(t) be velocity, and a(t) be acceleration We know: p(6.8) = 0 v(0) = 0 a = -9.8 v = (int)a dt = -9.8t + C Plug in v(0) = 0 0 = -9.8(0) + C therefore C = 0 p = (int)v dt = .5 * -9.8t² + C' (C' to indicate that it's different from the C above) = -4.9t² + C' Plug in p(6.8) = 0 0 = -4.9(6.8²) + C' C' = 226.576 Now check out p(0) for the initial height. p(0) = -4.9(0²) + 226.576 Therefore p(0) = 226.576 (Note the use of negatives throughout problem. Otherwise you will end up with your height as negative ![]() Also my answer is slightly different from theirs since I used 9.8 instead of 9.81 (which admittedly is slightly less accurate, but 9.8 / 2 is nicer than 9.81 / 2 ![]() Edit: Obviously this is a simple physics problem btw, and no I would not solve it this way if I actually wanted to get the answer. However, I assumed he wasn't supposed to just plug it into one of the physics equations. Sidenote: speaking of physics, C is initial velocity and C' is initial position. | ||
ilovejonn
Canada2548 Posts
>____> | ||
Meta
United States6225 Posts
On October 18 2007 09:33 ilovejonn wrote: Shitt...so many smart guys on TL.net, next time I gotta bring up some homework questions too.... >____> haha, last year we had a crusade against homework threads, although now that there's a blog feature i don't think that would be much of a big deal anymore ![]() | ||
dancefayedance!~
396 Posts
| ||
![]()
Chill
Calgary25981 Posts
| ||
fight_or_flight
United States3988 Posts
On October 18 2007 10:28 Chill wrote: wtf where did hotbid even post in this blog? Ha, I was just about to ask....was typing... edit: isn't hotbid a law major? does he know calculus too?? | ||
| ||
![]() StarCraft 2 StarCraft: Brood War Britney Dota 2![]() ![]() Bisu ![]() Rain ![]() Horang2 ![]() GuemChi ![]() Hyuk ![]() EffOrt ![]() firebathero ![]() Mini ![]() BeSt ![]() [ Show more ] Counter-Strike Other Games gofns30372 tarik_tv19943 B2W.Neo1000 RotterdaM566 hiko531 DeMusliM517 crisheroes378 Hui .361 XaKoH ![]() Liquid`VortiX112 Sick91 TKL ![]() QueenE70 NeuroSwarm41 Trikslyr28 ZerO(Twitch)14 Organizations StarCraft: Brood War StarCraft 2 StarCraft: Brood War
StarCraft 2 StarCraft: Brood War Dota 2 League of Legends Other Games |
OSC
Cure vs Iba
MaxPax vs Lemon
Gerald vs ArT
Solar vs goblin
Nicoract vs TBD
Spirit vs Percival
Cham vs TBD
ByuN vs Jumy
RSL Revival
Maru vs Reynor
Cure vs TriGGeR
Map Test Tournament
The PondCast
RSL Revival
Zoun vs Classic
Korean StarCraft League
BSL Open LAN 2025 - War…
RSL Revival
BSL Open LAN 2025 - War…
RSL Revival
[ Show More ] Online Event
Wardi Open
Monday Night Weeklies
Sparkling Tuna Cup
LiuLi Cup
|
|