Reading Questions 9.1††††††††††††††††††††††††††††††††††††††††††††††††† Name
Work, Power, and Machines pp. 284-290†††††††
- Write the four objectives of this section.
- When is work done?
- How is work calculated?
- Why donít you do work when you try to lift a car?
- Is the weight lifter in Figure 9-1 doing work?
- What are the three units for work?
- How big is a J?
- Look at the practice hint, how do you get force, when
it gives you kilograms?
- What is power?
- Why does running up the stairs use more power than
walking up thes tairs?
- What units is power measured in?
- What is horsepower?
- How does a jack make it easier to lift a car?
- What two ways can machine make doing work easier?
- Compare the amount of work done in Figure 9-3A and
- Compare the amount of force needed in Figure 9-3A and
- How do a car jack and a ramp make doing work easier?
- What is mechanical advantage?
- How is mechanical advantage calculated?
- What does it mean if a machine has a mechanical
advantage greater than one?
- What does it mean if a machine has a mechanical advantage
less than one?