Final answer:
The total amount of physical capital available in a country is known as the country's capital stock. Capital stock includes the plant and equipment that firms use, as well as infrastructure like roads.
Step-by-step explanation:
The total amount of physical capital available in a country is known as the country's capital stock. Capital stock includes the plant and equipment that firms use, as well as infrastructure like roads. It can affect productivity by increasing the quantity or quality of physical capital.