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Dive into chapter 8 concepts on work and power, create presentations, and test questions. Learn about forces, distances, power calculation, and application through example problems.
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Assignment • I will number you into groups. • You will be working in chapter 8 of the book. • Your group number will represent your section of the chapter.
Expectations • You will be presenting your section to class. • The method of presentation is your choice. (notes, demonstrations, vocab game…) • Your group will also generate 5 test questions (multiple guess / calculations)
Work • Work – a force applied over a distance • W= F(d) • units: F=Newton d=meter W= Joules
W = F x d Therefore: You must have MOTION in order to have work… something has to change position
Power • Power – the rate at which work is done • Power = Work/time • Unit is Watt (joule/second)
Example Problems If a 450 N boulder is dropped 2.4 m in 25 seconds, how much power is exerted on the object?
Example Problems How much work is done by a toy car with an applied force of 12 N which is moved for 39 m?
The weight lifter lifted a mass of 100 kg (barbell) over her head in 5.21 seconds. Approximately how much power did she generate in raising the barbell?
Example Problems A mechanic used a hydraulic lift to raise a 12,054 N car 1.89 m above the floor of a garage. It took 4.75 s to raise the car. What was the power output of the lift?