Answer Happy

(b) As part of a student competition, you need to design the drive system for an electric scooter. The scooter is driven by the front wheel, which is driven by a single electric motor. The competition regulations state that it must accelerate from 0 to 8 mph in 7.6 seconds, for a given torque T. You measure the speed of the wheel at 8 mph and determine that it is rotating at 2000 rpm. You consult the spec sheet of a cheap motor that you are considering, which states that with the same torque T, the motor would accelerate from rest to 2000 rpm in 1.9 seconds, assuming the damping and losses to be negligible. The wheel is assumed to be a solid cylinder, with inertia of Jcyl = 3.8 kg.m?, excluding the motor. The inertia of this system is composed of the unicycle's wheel (Jcyl), as well as the inertia of the motor. The wheel is assumed to run at the same speed as the motor (no gearbox). The motor torque cannot exceed 125 Nm. Determine if this motor torque will be sufficient to accelerate the scooter as required. [8 marks]