Question

Figure 13 shows a pulley system used to raise a mass of 5 kg through a height of 2 m when a force of 60N is applied. (Acceleration due to gravity g is 10ms^-2)


Determine the:

1. distance moved by the effort; 
2. work done on the load; 
3. potential energy gained by the load (g = 10 Nkg^-1). 

Answer 1

1. Effort = 2 x load distance
   = 2x2
   =alternatively:
   V.R = Effort distance  
              Load distance
   Effort distance = V.r x load distance
   = 2 x 2
   = 4
2. Work done 
   = F x D
   = 5 x 10 x 2
   = 100J
3. PE = Work done
   = 100j 
   ( 5 x 10 x 2) = 100J