Numerade

Questions asked

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Nishant Kumar

Numerade educator

A thin (circular) disk of radius 0.0350 cm at 20 ° C is made of lead. Determine the change in area when it is heated to 625 ° C. Consider that the coefficient of linear expansion is 29.0 × 10?6 / C?.

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Christopher Dzorkpata

Numerade educator

Suppose you have a pot full of steam at 110 ° C and a pressure of 1 atm. The pot has a diameter of 20 cm and a height of 15 cm. Place a heavy stone on the lid so that the combined mass of the lid and the stone is 45 kg. How hot do you need to heat the steam to lift the lid of the pot?

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Nishant Kumar

Numerade educator

A typical donut contains 3.7 g of protein, 17.6 g of carbohydrates and 6.1 g of fat. The average dietary energy values ??of these substances are 4.0 kcal / g for proteins and carbohydrates, and 9.0 kcal / g for fats. If the energy in the donut could somehow be converted to the kinetic energy of your body as a whole, how fast could you move after eating the donut? Consider its mass to be 55.4 kg, plus 1 cal = 4.186 J

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Nishant Kumar

Numerade educator

Fifty grams of ice at 0 ° C are placed in a thermos containing one hundred grams of water at 6 ° C. How many grams of ice will melt? The latent heat of fusion of water is 333 kJ / kg and the specific heat is 4190 J / kg · ºC.

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Nishant Kumar

Numerade educator

Se colocan cincuenta gramos de hielo a 0°C en un termo que contiene cien gramos de agua a 6°C. ¿Cuántos gramos de hielo se derretirán? El calor latente de fusión del agua es 333 kJ /kg y el calor específico es 4190 J / kg·ºC.

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Linda Winkler

Numerade educator

Una sustancia se comprime desde un volumen V_i = 1 m³ hasta un volumen V_f =V_i/3 de manera que la presión P de la sustancia varía con respecto al volumen V mediante la siguiente función P = 4000 / (V + V²) Donde la presión está medida en pascales. La energía interna E_int de la sustancia solo depende del volumen mediante la siguiente función E_int = 3000 / V Con la energía medida en Joules. a) ¿Cuáles son los valores iniciales y finales de la energía interna y la presión? b) Calcule el cambio en la energía interna de la sustancia durante este proceso c) Calcule el trabajo realizado sobre la sustancia durante este proceso. d) Calcule el calor transmitido durante este proceso. ¿El calor está siendo extraído o agregado a la sustancia?

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Ajay Singhal

Numerade educator

A gas sample of N2 (Molecular Mass: 0.028kg / mol) is compressed, at a constant pressure of 0.88Pa, from 22L to 12L. Its initial temperature is 20 ° C. Calculate: (a) The initial temperature in degrees Kelvin (b) The temperature at the end of compression in absolute and centrifugal scale (c) the number of moles in the sample (d) the density (in kg / m3) before and after compression (e) and the number of molecules present in the experiment Assume that the number of molecules during the process remains constant.

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Nishant Kumar

Numerade educator

Inside a sphere of radius r = 12cm there are 8 × 1023 gas molecules at a temperature of 50oC. What pressure do the molecules exert inside the sphere?

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Ajay Singhal

Numerade educator

The ends of the bars shown in the figure are 5 mm apart at 25 ° C. The left hand bar is brass and is 1.00 m long, and the right hand bar is steel and is 1.00 m long as well, assuming the outer ends of both bars are firmly supported against rigid supports. a) Determine at what temperature the ends of the facing bars just touch. b) If only 5 µm were separated, what would now be the necessary temperature to join them?

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Cristopher C.