Pressure cookers, in general, maintain a gage pressure of 2 atm (or 3 atm absolute) inside. Therefore, pressure cookers cook at a temperature of about 133°C instead of 100°C, cutting the cooking time by as much as 70 percent while minimizing the loss of nutrients. The newer pressure cookers use a spring valve with several pressure settings rather than a weight on the cover. A certain pressure cooker has a volume of 6 L and an operating pressure of 75 kPa gage. Initially, it contains 1 kg of water. Heat is supplied to the pressure cooker at a rate of 500 W for 30 min after the operating pressure is reached. Assuming an atmospheric pressure of 100 kPa, determine the temperature at which cooking takes place.

Pressure cookers, in general, maintain a gage pressure of 2 atm (or 3 atm absolute) inside. Therefore, pressure cookers cook at a temperature of about 133°C instead of 100°C, cutting the cooking time by as much as 70 percent while minimizing the loss of nutrients. The newer pressure cookers use a spring valve with several pressure settings rather than a weight on the cover. A certain pressure cooker has a volume of 6 L and an operating pressure of 75 kPa gage. Initially, it contains 1 kg of water. Heat is supplied to the pressure cooker at a rate of 500 W for 30 min after the operating pressure is reached. Assuming an atmospheric pressure of 100 kPa, determine the amount of water left in the pressure cooker at the end of the process.

Consider 0.8-cm-diameter hail that is falling freely in atmospheric air at 1 atm and 5°C. Determine the terminal velocity of the hail. Take the density of hail to be 910 kg/m3. Take the density and kinematic viscosity of air at 1 atm and 5°C as ρ = 1.269 kg/m3 and v = 1.382 × 10–5 m2/s. The figure for the average drag coefficient for cross-flow over a smooth circular cylinder and a smooth sphere is given below. Find the terminal velocity of the hail:

A solid ball is dropped into a water container for cooling. The ball has a diameter of D = 4 mm and sinks at a constant terminal velocity of Ut = 0.01 m/s. The thermophysical properties of the solid ball are: density ρ = 8000 kg/m3, thermal conductivity k = 200 W/m · K, and specific heat c = 1000 J/kg · K. The thermophysical properties of the water are: density ρw = 1000 kg/m3, kinematic viscosity νw = 10^(−6) m^(2)/s, thermal conductivity kw = 0.6 W/m · K, and Prandtl number Pr = 7. The vertical distance for the ball to sink from the initial fully submerged depth to the bottom of the container is H = 0.1 m. The initial temperature of the ball is T0 = 800 K, and the water temperature is T∞ = 300 K.Given correlations: For the convection heat transfer caused by flow past a sphere, the averaged Nusselt number is NuD = 2 + 0.6*(Re^(1/2))*(Pr^(1/3)) Questions:(1) Determine the averaged convection heat transfer coefficient h, and check if the LumpedCapacitance Method can be used to solve…

Q1/ How does the dynamic viscosity of (a) liquids and (b) gases vary withtemperature?   Q2/  What does the friction coefficient represent in flow over a flat plate? How is itrelated to the drag force acting on the plate?

4.2. The ball catathermometer factor (F) is 620, time while the spirit column drops from 38 to 350C in 100 seconds and the air temperature is 260C. Determine the air movement speed for the industrial section with these parameters.

Given the following measurements of mean winds and temperature from a 200-m mast in Netherlands on a September night: Table 1. Measurements of mean winds and temperature from a 200-m mast in Netherlands on a September night.   Question: Determine the Richardson number (Ri) at heights of 7.5, 15, 30, 60, 100, 140, and 180 m (note: ∂Θ/∂z at height 7.5 m is the potential temperature gradient between 5 m and 10 m).

What are the physical and quantitative evidence of turbulence in fluid flow?

The viscous laminar flow of air over a flat plate results in the formation of a boundary layer. The boundary layer thickness at the end of the plate of length L is Delta L . When the plate length is increased to twice its original length. The percentage change in laminar boundary layer thickness at the end of the plate (with respect to Delta L ) is ______