In the early 1880s, a bicycle nicknamed the “penny farthing” became popular. It
ID: 1361055 • Letter: I
Question
In the early 1880s, a bicycle nicknamed the “penny farthing” became popular. It featured an extraordinarily large front wheel and pedals placed relatively close to that wheel’s axis of rotation, as shown in Figure 1.
Figure 1
The penny farthing was constructed in such as way that each revolution of the rider’s legs produced one revolution of the wheel, although the circumference of the rider’s revolution was much smaller than that of the wheel itself. Many attempts were made to improve on the penny farthing in order to afford the rider more mechanical advantage. One variation extended the lengths of the shafts on which the pedals were held so that the rider’s legs would travel a larger circumference, as shown in Figure 2.
Figure 2
Later advances in mechanical engineering led to a bicycle on which the pedals drove a toothed sprocket connected by a flexible chain to a toothed sprocket on the rear wheel. Later, an option to move the chain laterally at both the rear sprocket and the front sprocket, within the control of the rider, provided the possibility of positioning the chain on relatively larger or smaller sprockets to adjust the mechanical advantage. The larger sprockets on the rear afforded the rider a greater degree of mechanical
advantage than did the smaller ones. On the contrary, a rider will have more difficulty riding uphill with the chain revolving about the largest front gear since that requires a greater force.
Increased efficiency was also achieved by the advent of the pneumatic tire and by the subsequent narrowing of its gauge.
What was the benefit of the modified penny farthing shown in Figure 2?
A) Reduce the amount work performed by the rider
B) Reduce the amount of force applied on the pedals by the rider
C) Increase the velocity attained for any given amount of work
D) Increase the kinetic energy attained for any given amount of work
Explanation / Answer
The benefit of the modified penny farthing shown in Figure 2 was to reduce the amount of force applied on the pedals by the rider.so option (B) is correct.