Elephant in the way kinetic energy problem.

[Bob Loblaw]

"Elephant in the way" kinetic energy problem.

Homework Statement

http:/www.imgred.com/http://static.scribd.com/docs/736egzypod07v_files/image004.jpg

I found this on one of those "OMG FUNNY" internet web pages. I am trying to attempt a solution.

Homework Equations

Mechanical energy is conserved so Einitial=Efinal. Uinitial+Kinitial=Ufinal+Kfinal.
mgyinitial+1/2mvinitial^2=mgyfinal+1/2mvfinal^2

The Attempt at a Solution

KE+PE = Total Energy. When the 3kg object is released from a 5m. I am unsure on how to procede with this problem. How does the force constant k of the spring factor into the solution?

 

[Calbear]

You're doing it wrong.
How to do this problem:
U(initial) {which is gravitational potential energy} = mgh, where h is 5m, m is 3kg, g is 9.81m/s^2.
U(final) {which is elastic potential energy} = 1/2kx^2, where k is 100.
WE WANT X.
W=delta E
Conservation of energy in sys mass, plane, earth. W=0
0=1/2kx^2 - mgh
mgh=1/2kx^2
(2mgh)/k=x^2
So, x=Square Root ((2mgh)/k)
So, the answer in this problem is SqRt((2(3kg)(9.81m/s^2)(5m))/100)
~SqRt 3 = 1.73205 meters

Hope that helped, if you care at this point, months later.

 

[Moetasim]

I would first clarify the problem statement and make sure all the relevant information is provided. What is the 3kg object? Is it the elephant mentioned in the title? If so, what are its initial and final positions? What is the 5m referring to? Is it the distance the 3kg object is released from?

Once the problem is clearly defined, I would then proceed with solving it using the given equations and principles of conservation of energy. The force constant of the spring, k, would play a role in calculating the potential energy of the spring, which would be converted into kinetic energy as the 3kg object is released.

I would also consider the mass of the elephant and factor it into the calculation, as it would have a significant impact on the final result. Furthermore, I would also take into account any external factors, such as friction or air resistance, that may affect the energy conservation.

Overall, the solution to this problem would require careful analysis and consideration of all the relevant factors. As a scientist, it is important to approach problems with a clear and systematic mindset, and to make sure all necessary information is provided before attempting a solution.