<p>a chain is placed on a edge of a frictionless surface, and it has a mass of m and a length of L, 1/4 of it is hanged in the air and 3/4 is on the table. how much energy is needed to pull the hanging part onto the table?</p>
<p>the diagram is somthing like the following</p>
<p>----------3/4---------> F
|<br>
|
1/4
|
\/
mg</p>
<p>i think for this problem i need to use calculus do i?</p>
<p>w = integral of f(x) dx</p>
<p>and f(x) = mg, which here m = the mass of the hanging part, let's say x is the length variable</p>
<p>so f(x) = x/L * m * g</p>
<p>and the integral is from L/4 to 0</p>
<p>w = ..........................</p>
<p>ok i got it, haha. its hard to take AP physics C without AP calculus, Im taking pre-cal honor. so i messed up with the calculus part, and i checked it and got the right answer which is mgL/32</p>