**Given Information:**

Inlet velocity = Vin = 25 m/s

Exit velocity = Vout = 250 m/s

Exit Temperature = Tout = 300K

Exit Pressure = Pout = 100 kPa

**Required Information:**

Inlet Temperature of argon = ?

Inlet Temperature of helium = ?

Inlet Temperature of nitrogen = ?

**Answer:**

Inlet Temperature of argon = 360K

Inlet Temperature of helium = 306K

Inlet Temperature of nitrogen = 330K

**Explanation:**

Recall that the energy equation is given by

Where Cp is the specific heat constant of the gas.

Re-arranging the equation for inlet temperature

**For Argon Gas:**

The specific heat constant of argon is given by (from ideal gas properties table)

So, the inlet temperature of argon is

**For Helium Gas:**

The specific heat constant of helium is given by (from ideal gas properties table)

So, the inlet temperature of helium is

**For Nitrogen Gas:**

The specific heat constant of nitrogen is given by (from ideal gas properties table)

So, the inlet temperature of nitrogen is

Note: Answers are rounded to the nearest whole numbers.