Passage IV

Two types of friction affecting bicycle riders are:

· air resistance

· rolling resistance between the tires and the ground

Table 1 gives the air resistance, RA, affecting a rider moving at speed V when the cross-sectional area of the rider plus bicycle equaled X. Table 1 also gives the power, PA, in watts (W), the rider had to generate to compensate for RA to maintain V. Figure 1 gives the power, PA + R, in horsepower (hp), a rider had to generate to compensate for RA plus rolling resistance to maintain V = 5.6 m/sec or 11. 2 m/sec for a wheel diameter of 16 inches or 27 inches and various tire pressures. Figure 2 is a graph of power in W versus power in hp.

Figure 1 adapted from Frank Roland Whitt and David Gordon Wilson, "Bicycling Science." @1974 by The Massachusetts institute of Technology.

17. Suppose that for a particular bicycle and rider. X equals 0.33 m2. Based on Table 1, RA for this bicycle and rider will equal 2.9 N if V equals:

Answer and Explanation

Your Answer is

Correct Answer is B

Explanation

RA=2.9 given in the question stem is between 1.7-5.8 in table 1;

When X=0.33 m2, V is between 3.0 Between -5.6, 4.0 of option B meets