A group of students are carried to the top of a drop tower ride at an amusement park. Suddenly the chair drops straight down the tower track. The brakes slow their motion as they approach the ground. Describe the changes in their motion and how their energy transfers from their position at the top of the ride to the bottom.

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

Which of these statements is true? a. quarks pair with leptons to form protons and neutrons. b. quarks pair with bosons to form photons. c. quarks pair with photons to form protons and neutrons. d. quarks pair with other quarks to form protons and neutrons. e. quarks pair with electrons to form protons.

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.