In our widget example, we will assume that the fixed cost for the stapler, pen, and âfactoryâ is $10 and the cost of each worker hired is $5 per worker. Since fixed costs are constant, the firm incurs $10 regardless of the level of output. Labor is the only variable cost computed by $5 times the number of workers.
How Bull Sharks Can Live in Both Ocean and Fresh Water. Although there are a handful of species that live in freshwater, we tend to think of sharks as being ocean dwellers. But there is also a very unique shark that can live in both ocean and fresh water estuaries and lakes: the Bull Shark.
Some sharks are fast and some sharks are slow, but the great majority cruise at very low speeds. While great whites, blues, and makos are capable of a great speed burst, most sharks swim at around 1.5 miles per hour when they're not actively chasing prey or attempting to escape from a dangerous situation. This speed falls about in line with the average human swim speed, which is between 1 and 2 miles per hour.