In a belt transmission dynamometer, the distance between the centre of driving pulley and dead weights is \(1 \mathrm{~m}\). Find the value of dead weights required to keep the lever in horizontal position if power transmitted is \(7.5 \mathrm{~kW}\) and the diameter of each of the driving as well as the intermediate pulleys is equal to \(0.4 \mathrm{~m}\). The driving pulley runs at \(400 \mathrm{rpm}\).