Old faithful geyser shoots water every hour to a height of 40.0 m. With what velocity does the water leave the ground? (disregard air resistance; g=9.81m/s^2.)
A. 7.00 m/s
B. 14.0 m/s
C. 19.8 m/s
D. 28.0m/s
2006-12-04 13:28:57 · 9 answers · asked by strawberrylollipop12345 1 in Science & Mathematics ➔ Physics
C
2006-12-04 13:30:00 · answer #1 · answered by KO 3 · 0⤊ 0⤋
use the following two formulae
s=ut +1/2 a t^2
v=u + at
Where s= distance (40.0 metres)
u= initial velocity (ie the velocity that the water leaves the ground)
t= time in seconds
v=final velocity (at the top of it's travel the water stops before falling back down so v=0 m/s)
put v into the bottom equation and get t=u/9.81
(don't forget that gravity is DEcelerating the water so acts in a negative direction. ie 0=u-9.81t)
substitute this value for t into the top equation and get
40=(u^2)/9.81 - (4.905u^2)/(9.81^2)
solve for u to get your answer.
approximately 28 m/s
Alternatively I think there is a simpler formula but I can't remember it so this way will have to do.
2006-12-04 21:58:21 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Use this equation: 2ad = Vf^2 -Vi^2.
"a" is 9.81
Vf is the velocity of the water at the highest point (which is 0 because the water stops rising at the highest point)
"d" is 40.0 m
Solve for Vi (the initial velocity)
2006-12-04 21:31:54 · answer #3 · answered by kdesky3 2 · 0⤊ 0⤋
You have to use the the formula:
The Y component of the system:
d = 40, a = -9.81, Vf = 0 m/s
d = (Vf^2 - Vi^2) / 2a
40 * (2 * -9.81) = -Vi^2
Vi = 28 m/s
Therefore, Answer is D
2006-12-04 21:34:53 · answer #4 · answered by Darkness1089 2 · 1⤊ 0⤋
Look up on some website for the formula of velocity
Have you ever done your own homework before or do you just get other people to do it?
2006-12-04 21:33:32 · answer #5 · answered by Alex 5 · 0⤊ 0⤋
energy at the highest pt,
E = mgh
E = 9.81(40)(m)
m = mass of water.
Kinetic energy = Gravitational Potential energy
KE = (0.5)(m)(v)^2
v = velocity of water
therefore,
(0.5)(m)(v)^2 = 9.81(40)(m)
cancelling out the m, we get,
(0.5)(v)^2 = 9.81(40)
v = 28.0m/s (D)
2006-12-04 22:21:10 · answer #6 · answered by superlaminal 2 · 0⤊ 0⤋
Vf^2 = Vi^2 + *2*a*d
0 = Vi^2 +2*-9.8*40
Vi = 28
How did you guys get C??
2006-12-04 21:31:43 · answer #7 · answered by scubamasterme 3 · 1⤊ 0⤋
yellow stone is unstable..just like string theory !
2006-12-04 21:31:11 · answer #8 · answered by Anonymous · 0⤊ 0⤋
c
2006-12-04 21:30:15 · answer #9 · answered by cese1 2 · 0⤊ 0⤋