The posted speed limit on the road heading from your house to school is 45 mi/h, which is about 20 m/s. If you live 8 km (8,000 m) from school; a) How long ( in seconds) will it take you to get to school if there is no traffic? b) Convert your answer from part a) to the nearest whole number of minutes and remaining seconds.

The drag force, fd, imposed by the surrounding air on a vehicle moving with velocity v is given by fd = cdaρv 2/2 where cd is a constant called the drag coefficient, a is the projected frontal area of the vehicle, and ρ is the air density. an automobile is moving at v = 80 kilometers per hour with cd = 0.28, a = 2.3 m2, and ρ = 1.2 kg/m3.