Q1. A chair of weight 125 N lies atop a horizontal floor; the floor is not frictionless. You push on the chair with a force of F = 35.0 N directed at an angle of 42.0 below the horizontal and the chair slides along the floor. Using Newton's laws, compute the magnitude of the normal force that the floor exerts on the chair.
Express your answer in Newton's.
Q2. Two concrete spans of a 220 m long bridge are placed end to end so that no room is allowed for expansion. If a temperature increase of 20.0°C occurs, what is the height y to which the spans rise when they buckle?