Please be clear

Required information NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. A 1 meter wide tank has a 1 by 1 m square gate that is hinged at A as shown. A couple of magnitude 420 N m is required to open the gate. The tank is filled with water at a rate of 0.1 m^3/min. Determine at what time the gate will rotate. O 0.6 m Water 0.4 m 4 Determine at what time the gate will rotate. The gate will rotate after seconds