BALANCE IT from INJSO

An overhead crane is being erected to construct a multi-storied building . The horizontal arm of the crane has a linear mass density of 100 kg/m and is 50 m in length . Its short arm on the opposite side of the support is 5 m long.A pulley block on the long arm , which can be moved along the arm , weighs 500 kg . Ignore the mass of the vertical frame . the vertical frame will twist and break if there is an excess imbalance of more than 10 percent . What is the minimum counter balance required on the short arm which is to be installed on a permanent basis -

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