Why did the Articles of Confederation fail?

Write a 1000 word essay on the following:
Why did the Articles of Confederation fail? In your answer be sure to explain the powers of the state governments v. the powers of the national government.
How did the founders answer the question of the need for more effective government without destroying liberty, Liberty v. Tyranny, in drafting the
Constitution: In your answer explain how the Constitution provides greater national power but prevents tyranny? On the latter point be sure to discuss
separation of powers, checks and balances, protection of rights and federalism.