The flywheel shown in Fig P839 has a diameter of 260mm and t

The flywheel shown in Fig. P8.39 has a diameter of 260mm and the shaft has a diameter of 22mm. A cord is pegged to the shaft and then wrapped around it several times. A mass m of 80 g attached to the end of the cord lowers at a constant velocity after release. An additional mass of 1.5 kg attached to the first mass lowers 1.2 m in 12.6 s before the cord and mass drop off the shaft. The diameter of the cord is 2.5mm and the mass of the flywheel and shaft is 5.2kg. Determine:

a) bearing frictional torque

b) tension in the cord as the combined mass is lowering

c) mass moment of inertia of the flywheel and shaft

d) radius of gyration of the flywheel and shaft

e) number of revolutions made by the flywheel after the combined mass and cord drop off the shaft

Ans, a) 0.0096Nm b) 15.5N c) 0.146kgm² d) 168mm e) 292 revs. please show working out thank you.

Solution

The loaded four wheel trailer shown in Figure P8.10 has a total mass of 5t and is pulled along a level road. Average resistance to motion (friction and windage) is 2 per cent of the total weight and acts at the same horizontal level as the applied force P. Determine the normal reaction at each of the front and rear wheels when the trailer moves:

a) at constant velocity

b) with forward acceleration 1.5m/s².

(Average resistance to motion is 2% of total weight is not required.)