: Finding Mechanical Energy, Velocity, and Height

[hueyosie]

URGENT: Finding Mechanical Energy, Velocity, and Height

Homework Statement

http://www.mrfizix.com/home/energy_files/image051.gif

Homework Equations

E₀=E_F
PE=mgh
KE=(1/2)mv²

The Attempt at a Solution

I understand how to get the potential and kinetic energy values but I'm confused as to how to get the mechanical energy, velocity, and height values. Any help would be appreciated!

 

[mtayab1994]

Well Mechanical Energy is the sum of the pot. energy and kinetic energy at a certain point.
And to find the velocity you do the change in kinetic energy between two points equals the work, or you do it a more simpler way which is the Mechanical energy at one point equals the mechanical energy at another point.

 

[mtayab1994]

For example at point 1 PE=0 and KE=.5*60*8^2=1920 J. And the ME=PE+KE=1920J

 

[hueyosie]

For example at point 1 PE=0 and KE=.5*60*8^2=1920 J. And the ME=PE+KE=1920J

That makes a lot of sense! Thanks so much! :)

 

[mtayab1994]

Ok so just do the same for point 2. You will be able to calculate the potential energy first. Then use PE(1)+KE(1)=PE(2)+KE(2) to find the KE and then use ΔKE=W from 1 to 2 and so on until you finish. It's pretty easy.