joint supply is when the production of one good also results in the production of another.
an example of this would be steel and cars. if there is more production of steel, there can be a greater production of cars, as steel is used in the manufacturing of cars.
i have two examples: Joint Committee on the Library & Joint Committee on Conduct of Foriegn War
Land is sometimes in joint supply as joint supply is when one good is supplied for different purposes. Such as a cow being supplied for meat and leather, oil being supplied for oil and gas. Land is sometimes supplied for both housing and farming, mining and factories etc. I'm sure you can find some other examples off the top of your head. Sources: Alain Anderton's AS Level Economics Fifth Edition textbook.
i have two examples: Joint Committee on the Library & Joint Committee on Conduct of Foriegn War
The things on your legs, and the things on you arms!
According to the Economist's "Economics A
yes
yes
Both are a ball and socket type of joint.
The joint that allows the forearm to swing in all directions.
list examples of competitive supply
hinge joint
knee joint