suppose that this year's money supply is $500b, nominal gdp is $10trillion, and real gdp is $5trillion, what is the price level and velocity of money? and if velocity is constant and the economy's output rises by 5% per year, what will happen to nominal gdp and the price level next year if the Fed keeps the money supply constant?

To answer your questions, we need to use the quantity theory of money equation, which states that:

MV = PY

Where:
M = Money supply
V = Velocity of money (the average number of times a unit of money is spent in a given period)
P = Price level
Y = Real GDP (output or income)

Let's break down the information provided step by step:

1. Money supply (M) = $500 billion
2. Nominal GDP (PY) = $10 trillion
3. Real GDP (Y) = $5 trillion

Using the equation, we can find the velocity of money (V):

V = PY / M

Substituting the values:

V = $10 trillion / $500 billion
V = 20

So, the velocity of money is 20.

Next, we want to determine the price level (P). Rearranging the equation, we have:

P = (M * V) / Y

Plugging in the values:

P = ($500 billion * 20) / $5 trillion
P = 2

Therefore, the price level is 2.

Now, let's move on to the second part of your question. If velocity (V) is constant and the economy's output (Y) rises by 5%, we can determine the impact on nominal GDP (PY) and the price level (P).

Given that V and M remain constant:

PY = MV

Assuming the money supply (M) remains at $500 billion, if output (Y) increases by 5%, we can calculate the new nominal GDP (PY):

New Y = $5 trillion * (1 + 0.05)
New Y = $5.25 trillion

PY (next year) = $500 billion * 20 (constant velocity)
PY (next year) = $10 trillion

Hence, next year's nominal GDP will be $10 trillion.

To find the new price level (P) next year, we rearrange the equation:

P (next year) = (M * V) / Y (next year)

P (next year) = ($500 billion * 20) / $5.25 trillion
P (next year) ≈ 1.9048

Therefore, the price level next year will be approximately 1.9048.

In summary, if the Fed keeps the money supply constant and the economy's output rises by 5% per year, the nominal GDP will increase to $10 trillion, while the price level will decrease to approximately 1.9048.