The pressure of water is increased from 100 kPa to 900 kPa by a pump. The temperature of water also increases by 0.15°C. The density of water is 1 kg/L and its specific heat is cp = 4.18 kJ/kg⋅°C. The enthalpy change of the water during this process is kJ/kg. Solve this problem using appropriate software.

The enthalpy change of the water during the process is 1.4 kJ/kg

Explanation:

The enthalpy change of the water during the process can be determined from

Where

is the enthalpy change

is the change in pressure

is the density

is the specific heat

and is the temperature change

From the question

= 900 kPa - 100 k Pa

= 800 kPa

= 1 kg/L = 1kg/dm³ = 1000 kg/m³

= 4.18 kJ/kg.°C

= 0.15 °C

∴

Hence, the enthalpy change of the water during the process is 1.4 kJ/kg

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.