What is the slenderness ratio of a 4meter column with fixed ends if its cross-section is square…

What is the slenderness ratio of a 4meter column with fixed ends if its cross-section is square ofside 40mili meter?A cantilever beam, 2meter in length, is subjected to a uniformly distributed load of 5kilo Newton/meter. If E =200Giga Pascal and I = 1000 cm4, the strain energy stored in the beam will be