4.1 - Understanding forces
1. What is force?
2. How are forces classified? Provide examples for each.
3. What is mass? Weight? What is the proper unit for each? What's the relationship between mass and weight on Earth? How does this relationship change if you were on the moon?
4. Fg = mg
5. When you plot a weight vs. mass graph, what does the slope of the line represent? If Planet X has a steeper slope than Planet Y, which planet has stronger gravitational strength?
4.2 - Work and Energy
1. What is work? What's the proper unit? What is energy? How is work related to energy?
2. Energy can be transferred or transformed. Provide an example of each.
3. How is kinetic energy different from potential energy?
4. How does friction 'do work'?
5. W = fd
4.3 Mechanical Advantage
1. What is a machine?
2. Identify the 3 ways that machines help make our lives easier.
3. What is input force? What is output force?
4. MA = f out/ f in
5. Give an example of MA = 1
6. IMA = d in / d out
7. Is IMA >, < or = MA? Explain.
8. Explain why IMA < 1 may be desirable sometimes. Give an example.
5.1 Simple Machines
1. Identify the 6 simple machines.
2. Sketch the 3 different classes of lever. Provide a real-life example for each class.
3. Remember that the general formula for IMA is d in / d out, even though there are specific formulas for a lever, ramp, and wheel & axle. The important is knowing where is the input and where is the output.
5.2 Efficiency
1. Efficiency is about saving energy...the more efficient the machine, the less friction it has and therefore less heat is produced (i.e. less wasted energy).
2. Input work > output work. WHY?
3. Efficiency = W out / W in x 100%
4. What are some ways to increase efficiency?
