We see that for a particular wheel, supplied with water at some fixed flow rate (so that both m and v are also fixed), torque T varies as (1-y). The torque therefore falls linearly from a maximum when y = 0 (i.e. when the wheel is stationary) to zero when y = 1 (i.e. when the bucket moves at the same speed as the jet). This is referred to as the runaway condition.