1. A hydraulic lift office chair has its seat attached to a piston with an area of 11.2 cm². The chair is raised by exerting force on another piston, with an area
of 4.12 cm². If a person sitting on the chair exerts a downward force of 219 N,
what force needs to be exerted on the small piston to lift the seat?
09

Afeather of mass 0.001 kg falls from a height of 2 m. under realistic conditions, it experiences air resistance. based on what you know about friction, what can you say about the kinetic energy of the feather as it reaches the ground? acceleration due to gravity is g = 9.8 m/s2. a. ke < 0.0196 j b. ke = 00196 j c. je = 0 j d. ke > 0.0196 j

The dot diagram represents the motion of the motorcycle as it moves from left to right

Awater slide of length l has a vertical drop of h. abby's mass is m. an average friction force of magnitude f opposes her motion. she starts down the slide at initial speed vi. use work-energy ideas to develop an expression for her speed at the bottom of the slide. then evaluate your result using unit analysis and limiting case analysis. express your answer in terms of the variables h, m, l, vi, f and appropriate constants. vf v f