Physics: Viewer's Request: Mechanics #17: Conservation of Energy: Method 2 (Wife's Method)

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We will solve: An object of a 30 degree incline at an initial velocity v0. When it arrives back at the bottom, after having reached a distance d up the incline, it has a velocity of v0/1.2. What is the coefficient of friction=? Method 2 (Mr. van Biezen's Wifes's Method or The Better Method)

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[ptyptypty]

Okay, I changed my mind. I'm nominating the WIFE for a TED TALK .. sorry Michel .... :D (lol)

[TALKmd]

haha that's great "Wife Method" - that's good Title - Really!

[TALKmd]

IN the question description they told us "An Object ***Pushed*** UP" and i thought we need to add in the Equations the Force to Push it . and that's why i failed to get to the Solution .

how can know that Push is not an external force ? because of the V_0 ?

[emilesharshouh]

Sir, the question starts with 'an object is pushed" which implies an external force, shouldn't the first equation be written as: W + PE1+ KE1= PE2 + KE2 + E(lost)