labor market wage determination

A minimum wage is an example of a price floor. what’s an example of using supply and demand analysis, the effects on the labor market of imposing a minimum wage. Why would a government choose to impose a minimum wage?
Assuming that orange juice is a normal good. What would happen to the market for orange juice in each of the following cases:

A severe winter affects the orange crop in Florida
An advertising campaign emphasizing the health effects of consuming Vitamin C is launched
The price of grapefruit juice falls
Agricultural workers win a wage increase
3.What’s the difference between command-and-control and market oriented solutions to negative externalities? what’s an example of each employed in pollution control?
4.A firm produces 100 computers. Its total costs are $90,000 of which fixed costs are $20,000. What are its: Average Fixed Costs, Average Variable Costs and Average Total Costs? When it produces another computer its total costs rise to $90,500. What is the marginal cost of the 101st computer?
5.What alternatives do firms have when raising capital? What criteria do they use in choosing between them?