Question #2546b

1 Answer
Apr 6, 2017

See below

Explanation:

The question only makes sense if we take into account the mass of the string.

Reubens

The small element #dx# will have mass: #dm= M/L dx#, assuming the string is of uniform density.

The FBD for the small element requires:

#sum mathbf F = m mathbf a#

#implies T + dT - T = dm \ a#

#implies dT = M/L dx \ a#

#implies T = M/L a x + C#

#T(0) = 10 implies C = 10#

#T(L) = 20 implies 20 = M/La L + 10 #

#implies T = 10/L x + 10#

Which is simply a linear increase along the string which is what intuitively one would expect.