Awoman is riding a bicycle down an 18% slope. her velocity is 25 km/hr into an oncoming 2-km/hr wind. the air is at 15◦c and 101 kpa. assuming that the only forces affecting the speed are the weight and drag, calculate the drag coefficient if the frontal area is 0.6 m2 and the combined mass is 54 kg. speculate whether the rider is in the upright or racing position.

Asolid cylinder is concentric with a straight pipe. the cylinder is 0.5 m long and has an outside diameter of 8 cm. the pipe has an inside diameter of 8.5 cm. the annulus between the cylinder ad the pipe contains stationary oil. the oil has a specific gravity of 0.92 and a kinematic viscosity of 5.57 x 10-4 m2/s. most nearly, what is the force needed to move the cylinder along the pipe at a constant velocity of 1 m/s?