A metal bar is initially horizontal. The rotation point is 0.5m from the right end of the bar. A person applies an upward force at the right end of the bar with a magnitude of 100N. A person applies a force of 50N upward on the left end of the bar. The bar experiences a net torque of 12.5Nm due to the two applied forces. What is the distance between the rotation point and the left end of the bar?