THE WHEELBARROW AS A LEVER 



or 



Force x distance = Weight x distance, 

 2x2 = 4x1. 



FIG. 99. The wheelbarrow lightens labor. 



Move the 4-pound weight so that it is very near the ful- 

 crum, say but 6 inches from 



it ; then the spring balance 



registers a force only one 



fourth as great as the weight 



which it suspends. In other 



words a force of I at a dis- 

 tance of 24 inches (2 feet) is 



equivalent to a force of 4 at 



a distance of 6 inches. 

 One of the most useful 



levers of this type is the 



wheelbarrow (Fig. 99). The 



fulcrum is at the wheel, the 



force is at the handles, the weight is on the wheelbarrow. 



If the load is halfway from the fulcrum to the man's hands, 



the man will have to lift 

 with a force equal to 

 one half the load. If 

 the load is one fourth as 

 far from the fulcrum as 

 the man's hands, he will 

 need to lift with a force 

 only one fourth as great 

 as that of the load. 



This shows that in 

 loading a wheelbarrow, 

 it is important to ar- 

 range the load as near 



FIG. ioo. A modified wheelbarrow. to the wheel as possible. 



CL. GEN. SCI. II 



