14 3 Mechanical Advantage and Efficiency Mechanical Advantage

14. 3 Mechanical Advantage and Efficiency Mechanical Advantage • Mechanical advantage: number of times a machine____an input force • Measuring the actual forces acting on a machine Ideal Mechanical Advantage • M. A. in the absence of friction • M. A. is always______than ideal because of ________. • engineers often design machines that use low-friction materials and lubricants

14. 3 Mechanical Advantage and Efficiency The gondola uses the inclined plane formed by its supporting cable to more easily move people uphill. • The increased horizontal distance (_______) is greater than the vertical gain in height (_________). • The inclined cable gives the gondola a mechanical advantage greater than 1.

14. 3 Mechanical Advantage and Efficiency • The percentage of work input that becomes work output is the__________of a machine. • Because of friction, efficiency is always less than ______ • If the efficiency of a machine is 75%, then 75% of the work input becomes work output • Reducing______increases efficiency of a machine. • Roller bearings reduce friction of the rotating wheels • The bearings are also greased to reduce rolling friction

14. 3 Mechanical Advantage and Efficiency If a machine requires 10. 0 J of work input to operate, then what is the work output if the machine is 75% efficient?

14. 3 Mechanical Advantage and Efficiency Engineers analyze the flow pattern of a smoke trail to determine the fluid friction forces (______) acting on the vehicle. Engineers use these data to optimize a vehicle's shape for maximum fuel efficiency.