Question

# 17 A pulley system is used to lift a 5.00 kN load through a height of 1.50 m. The sýfixed pulley and the other pulley can move. The pulleys are

connected by a nylon ope, as shown.http:/kem consists of one The nylon rope will stretch when it is used in this way. The weight of the pulleys and the rope can be ignored, and you may assume that there is no friction in the pulleys. The properties of the nylon rope are: Young modulus of nylon2.70 GPa overall length of rope before adding the load6.00 m area of cross-section3.00 × 10 'm² (a) The greater the length of a rope, the smaller the stiffness of the rope.Explain why. (b) (i) Show that the stiffiness k-of the nylon rope is about 1.4× 10°N m itp://britis(ii) The pulley system lifts the 5.00KN weight at a steady rate. Determine the extension of the rope while the lift is taking place. (iii) Calculate the work done in stretching the rope. (c) Assess whether the stretching of the rope has a significant effect on the efficiency ofthe pulley system.(2

Fig: 1

Fig: 2

Fig: 3

Fig: 4

Fig: 5

Fig: 6

Fig: 7

Fig: 8

Fig: 9

Fig: 10

Fig: 11

Fig: 12

Fig: 13