A piston-cylinder device initially contains water liquid-vapor mixture at the pressure of 700 kPa. The liquid-vapor mixture has 0.1 m3 of liquid water and 0.9 m3 of water vapor. Heat is transferred at constant pressure until the temperature reaches 320 °C. (a) What is the initial temperature of the water

Given question is incomplete. The complete question is as follows.

A piston-cylinder device initially contains water liquid-vapor mixture at the pressure of 700 kPa. The liquid-vapor mixture has 0.1 m3 of liquid water and 0.9 m3 of water vapor. Heat is transferred at constant pressure until the temperature reaches 320 °C.

(a) What is the initial temperature of the water.

(b) Determine the total mass of the water.

Explanation:

(a) We are given that initially there are two phase regions present.

       Initial temperature = saturation temperature at 700 Kpa

                                       =

Hence, the initial temperature of the water is .

(b)  At 700 Kpa, the saturation pressure will be as follows.

So,    

                    = 90.25 kg

                    = 3.3 kg

Therefore, total mass will be calculated as follows.

               90.25 kg + 3.3 kg

            = 93.55 kg

Hence, total mass of the water is 93.55 kg.

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied