Answer Happy

Question 6 The truck shown in Fig Q6 carries a 1500 mm diameter spool of cable with a mass and inertia of 750 kg and 240 kgm², respectively. The combined truck and spool has a centre of gravity at G and a total mass of 2500 kg, which can be assumed to remain constant during acceleration of the truck. The truck is rear wheel drive, with an engine producing a maximum torque of 100 Nm. In first gear, the transmission ratio between the engine and wheels is 20:1 (reduction). The wheel radius is 250 mm. Consider the condition when the truck is accelerating from rest using the maximum torque from the engine. (a) Draw the free body diagram of the spool, neglecting any friction in the spool bearings. [5 marks] (b) Draw a free body diagram of the combined truck and spool neglecting any friction in the wheel bearings. [5 marks] (c) Calculation the tension in the cable T and the linear acceleration of the truck. [12 marks] (d) In some off-road conditions, the truck (with the cable no longer attached to an external point) operates over muddy ground where there is significant rolling drag. The rolling drag has been measured as (4 +3.5V²) kN where V is the forward velocity of the truck. Calculate the distance travelled by the truck when accelerating from rest to a speed of 1 m/s. 1650 750- A 1050 1800 Figure Q6 1800 PO B [3 marks]