I need some help with the below question,

Since the peak in 1976, per capita beef consumption in the United States has fallen by almost 30 per cent. Assuming that beef producers operate in a perfectly competitive market and face a constant cost industry:

(a)  Using diagrams, explain the short run effect of declining demand for beef for a typical farm and for the market.

(b) Using diagrams, explain the long run effect of declining demand for beef for a typical farm and for the market.