You can also notice the impact of market fluctuations on the firm’s profit. In a perfectly competitive market, when the market demand for a good changes, the price of this good is affected, thus increasing or reducing the difference between the firm’s marginal revenue (unit price) and its average cost that jointly determine how much profit the firm will make.
A Note on Theory: Firm Profit
\Pi=[P \cdot Q]-[AC \cdot Q]
\Pi - Firm Profit
P - Unit Price (MR)
AC - Average Cost
Q - Quantity Produced
Tip
You can change the unit price in the competitive market by clicking and dragging the black point up and down as well.