Name: __________________________________________ Period: ___ Date: _________

Dekalb Reads Assignment  9.1

Work Power and Machines

1. Define work.
2. How will you calculate work?
3. Write down work equation.
4. In what condition the work done becomes zero?
5. Look at figure 9-1. Is the weight lifter doing any work on the barbell by lifting it above her head?
6. Work is measured in ________________________________.
7. In terms of SI base units a Joule is equivalent to _________________________.
8. How much work do you do when you slowly lift an apple that is about 1 N to a distance of about 1 meter?
9. Define power.
10. Write down the equation for power.
11. What is the SI base unit for power?
12. Define Watt.
13. What is the symbol for power?
14. Which one needs less work- lifting a car by your self or using a jack?
15. How do machines help us do work?
16. What is " multiplying the force"?
17. How can you do the same amount of work with different amount of forces?
18. Define Mechanical Advantage.
19. Mechanical advantage is also defined as the ration between the ________________________
20. Mechanical advantage is also equal to _________________________.
21. Write down the mechanical advantage equation.