Question

Draw a block and tackle system of pulleys with a velocity ratio of 5 . A block and tackle with a velocity ratio of 5 is used to raised a mass of 25 kg through a vertical distance of 40 cm at a steady rate. If the effort is equal to 60 N, determine

a)the distance moved by the effort;

b)the work done by the effort in lifting the load;

c)the loss in energy involved in operating the machine.

Answer 1

a) $l=5\cdot0.4=2\ (m)$

b) $W=60\cdot2=120 \ (J)$

c) $W_0=mgh=25\cdot9.8\cdot0.4=98\ (J)$

The loss in energy $120-98=22\ (J)$