Final answer:
The statement is false. The change in materials used in brake linings would not directly impact the price of tennis racquets.
Step-by-step explanation:
The statement that if carmakers find that cotton balls work better than graphite in brake linings and stop buying graphite, then the price of tennis racquets will go down is False. The reason is that carmakers and tennis racquet manufacturers are separate industries with their own supply and demand dynamics.
The change in materials used in brake linings would not directly impact the price of tennis racquets. The price of tennis racquets would be determined by factors such as the cost of production, demand for tennis racquets, and competition in the market.