If the diameter of a bicycle is two feet then in order for the bicycle to travel 2 kilograms the bicycle will have to travel approximately 1,045 feet. The number of revolutions is 2km / circumference. As you know 1km equals 3,280 feet and so in order to find the value for 2km just simply multiply 3,280 by 2 and you should get 6,561.81. The circumference of a circle is 2piR so in order to find your revolutions you multiply the figure 2 by pi. Remember that pi is oftenly rounded off to a decimal of 3.14, so you simply multiply 2 by 3.14 times 6,561.81. the reason why you should multiply the 6,561.81 to your equation as well is simply because in order to find your number of revolutions you multiply 6,561.81 / 2pi. You should come out with the answer of 1,045 revolutions.