Question

Essay question: it takes a lot less effort to ride a bicycle 10 km on a flat road than to walk the same distance. Describe the various factors that a bike rider must spend energy on to maintain a constant speed. (In other words, where does the energy go? If you assigned a number to each of these, the sum would equal the calories burned while biking.) Compare these to how energy is spent while walking, and discuss why it makes sense that riding a bike is more energy efficient.

Answer 1

While cycling rotational friction is acting on bicycle which is very less in comparision to linear kinetic friction hence by cycling we can reduce friction force which result in minimizing energy loss.

Therfore major amount of energy lost in cycling are , rotational frictional work done and work done due to drag and in simple walking major energy losses are linear frictional work done and work done by drag.As we can see drag is present in both of them so determining factor is work done by friction which we already know that rotational friction is very less than linear friction hence energy lost in cycling is less and cycling is more efficient way to travel the same distance.