Which type of wall would make the best soundproofing for room? a. 1.0 centimeter thick glass b. two layers of 0.5 centimeter thick glass with 0.5 centimeters of air between them c. two layers of 0.5 centimeter thick glass with 0.3 centimeters of vacuum between them d. 1.0 centimeter thick steel

Consider a small frictionless puck perched at the top of a fixed sphere of radius r. if the puck is given a tiny nudge so that it begins to slide down, through what vertical height will it descend before it leaves the surface of the sphere? [hint: use conservation of energy to find the puck's speed as a func e conservation of energy to find the puck's speed as a function of its height at what value of this normal force does the puck leave the sphere? ] here on the puck.