6. A roller coaster is designed so that the car is pulled up to the top of the first hill by a chain and
pulley system. After that, however, the car coasts the rest of the way through the track, never being
pulled or pushed again until its brakes stop it. Under these conditions, what is wrong with the roller
coaster designed below?

An architect plans to use solar energy to heat the next house he designs. what principle of absorption and infrared energy can be applied to the design of the new house? how could she apply to those principals?

A5 foot by 5 foot box culvert is buried 6 feet beneath the surface of the ground. a crosssection of this very long culvert (into and out of the page) is illustrated below. assume that the soil in which the culvert is buried has the following properties: jt = 120 pcf, w = 12%, ko = 0.50, ka = 0.33, and kp = 3.00. calculate the total horizontal force per unit length of culvert (fh) felt on one of the vertical faces of the culvert.

At what time will the interfering waves have an amplitudeof zero?