Calculate the time microwave oven takes to heat the pizza

Assignment Help Physics

Reference no: EM13997747

Application: Heating Food in a Microwave Oven. A frozen pizza is marketed to be heated in a microwave oven. As an engineer you are asked to write heating instructions, specifically how long should it be heated to reach a proper temperature. The average residential microwave oven is 50 cm wide, 40 cm deep, and 30 cm high. The oven has a low and a high heating level. At low, it produces a time averaged power of 500 W, whereas at high, the power is 1000 W.

We will assume the pizza is placed flat on the bottom of the oven and any power coupled into the pizza enters from above. The pizza is 25 cm in diameter, 1.5 cm thick, and is 75 % water by volume. The microwave oven heats the water in the pizza. The frozen pizza is at 20 ^oC and must be heated to 75 C. Heat capacity of water is 4.1885 J/ (gK) and the latent heat (of melting ice) is 334 J/g (heat capacity is the energy needed to raise the temperature of one gram of substance (water in this case) by 1 degree Kelvin, and latent heat is the energy required to melt a gram of ice at 0 ^oC to water at 0 ^oC). Assume that the heat transfer from the electromagnetic waves to the pizza is 80 % efficient and calculate:

(a) The time it takes to heat the pizza on the low setting of the oven.
(b) The time it takes to heat the pizza on the high setting of the oven.
(c) The cost in electricity to heat the pizza if a kW h costs $0.16.

Reference no: EM13997747

Questions Cloud

Find the shortest wavelength of the paschen series : Find the shortest wavelength of the Paschen series for Li2+ and the ionization energy required to remove the final electron in Li2+.

Which of the statements is true regarding job sharing : A good proportion of the company's prized workforce comprises employees from the baby boomer generation who are set to retire in the impending future.

How long after switch closed will voltage across capacitor : A simple RC circuit consists of a 1μF capacitor in series with a 2800-Ω resistor, a 6-V battery, and an open switch. Initially, the capacitor is uncharged. How long after the switch is closed will the voltage across the capacitor be 4.1 V?

Best describes the most literal meaning of guanxi : In international business settings, one of the most common ethical problems encountered involves employment practices.

Calculate the time microwave oven takes to heat the pizza : Calculate the time it takes to heat the pizza on the low setting of the oven, the time it takes to heat the pizza on the high setting of the oven and the cost in electricity to heat the pizza if a kW h costs $0.16.

What angular frequency does the loop rotate : A single conducting loop with an area of 2.0 m2 rotates in a uniform magnetic field so that the induced emf has a sinusoidal time dependence as shown.With what angular frequency does the loop rotate?

Use the dot product determine v and w are orthogonal : Use the dot product to determine whether v and w are orthogonal. Find projwv. Then decompose v into two vectors, v1 and v2, where v1 is parallel to w and v2 is orthogonal to w

What is the uncertainty in the time constant found : An apparatus similar to the one used in RC Circuits experiment is used. What is the time constant? What is the uncertainty in the time constant found above?

What distance is the second minima located from the center : A single slit is illuminated with light of wavelength 632.8 nm. The width of the slit is 79.5micrometers and the light is reflecting off a screen 1.90m behind the slit. At what distance is the first maxima located from the center of the pattern?

User Account

All Pages