1. Work and Power

2. 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.

3. 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)

4. Work Work – a force applied over a distance W= F(d) units: F=Newton d=meter W= Joules

5. W = F x d Therefore: You must have MOTION in order to have work… something has to change position

6. Power Power – the rate at which work is done Power = Work/time Unit is Watt (joule/second)

7. Example Problems If a 450 N boulder is dropped 2.4 m in 25 seconds, how much power is exerted on the object?

8. Example Problems How much work is done by a toy car with an applied force of 12 N which is moved for 39 m?

9. 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?

10. 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? Example Problems