📘 thermodynamics

1. **State the problem:** A mass of 0.25 kg of ice at -32°C is placed in water at 0°C. When thermal equilibrium is reached, the temperature is 0°C. We need to show that about 50 g

1. **State the problem:** We are given that 1,700 British thermal units (Btu) are converted into useful work, and the total energy supplied is 4,300 Btu. We need to find the therma

1. مسئله: ۲۰۰ گرم آب با دمای ۴۰ درجه سلسیوس را با مقداری یخ با دمای ۴۰- درجه سلسیوس مخلوط می‌کنیم تا دمای تعادل صفر درجه سلسیوس شود. مقدار حداقل یخ را بیابید. 2. فرمول‌ها و مفروضات

1. مسئله: یک قطعه یخ صفر درجه سلسیوس را درون ۱۰ گرم آب ۴۰ درجه سلسیوس می‌اندازیم. پس از تعادل گرمایی، ۱۰ گرم یخ ذوب نشده باقی می‌ماند. جرم اولیه یخ چقدر بوده است؟ 2. فرمول‌ها و داد

1. مسئله: یخ با جرم اولیه ۴۲۰ گرم در آب با دمای ۰ درجه سلسیوس قرار می‌گیرد و پس از تعادل، جرم یخ به ۴۱۰ گرم می‌رسد. دمای اولیه یخ را بیابید. 2. فرمول‌ها و مفاهیم مهم:

1. **State the problem:** A heat engine operates between a hot reservoir at temperature $T_H = 400$ K and a cold reservoir at temperature $T_C = 280$ K. The manufacturer claims the

1. **State the problem:** Calculate the efficiency of a Carnot cycle with a cold reservoir at 0.0 ºC and a hot reservoir at 110 ºC. 2. **Formula:** The efficiency $\eta$ of a Carno

1. The problem asks to analyze the thermodynamic process shown in the triangle labeled Fig. 2 with vertices A, B, and C, where side BA is vertical with length $P$ (pressure) and si

1. **State the problem:** We have a reversible no-flow process where the work done is $-156.2$ kJ, initial volume $V_1 = 0.845$ m³, and pressure varies with volume as $p = -730V +

1. **State the problem:** We have 500 mg (0.5 g) of iron at 200°C placed into 250 g of water at 20°C. We want to find the final temperature $T_f$ of the mixture after thermal equil

1. **State the problem:** We want to calculate the pressure $P$ of a real gas using the van der Waals equation of state: $$\left(P + \frac{n^2 a}{V^2}\right)(V - nb) = nRT$$

1. **State the problem:** We need to find the input horsepower (HP) required to drive a compressor delivering 5,099 SCFM at 139.6 psia with an overall efficiency of 83%. 2. **Formu

1. The problem asks to identify the correct representation of the second law of thermodynamics from the given options. 2. The second law of thermodynamics states that the total ent

1. The problem asks for the specific heat capacity at constant pressure (cp) of steam. 2. Specific heat capacity at constant pressure, $c_p$, is the amount of heat required to rais

1. **Problem:** Define temperature. 2. **Step 1:** Temperature is a measure of the average kinetic energy of the particles in a substance. It indicates how hot or cold an object is

1. **State the problem:** Define temperature, absolute temperature scale corresponding to Fahrenheit, and convert 100° F to that absolute scale. 2. **Definition of temperature:** T

1. Problem: Define temperature, absolute temperature scale corresponding to Fahrenheit, and convert 100° F to that scale. 2. Temperature is a measure of the average kinetic energy

1. Problem: A 2 kg object is moving at a velocity of 3 m/s. Calculate its kinetic energy (KE) in SI units and then convert it to English units (foot-pounds). 2. Formula: Kinetic en

1. **Problem Statement:** Calculate the kinetic energy (KE) and potential energy (PE) of an object in thermodynamics context, given mass, velocity, and height. Use both SI and Engl

1. **Stating the problem:** We are given the formula for heat transfer rate $$Q = \dot{m} \cdot c_p \cdot (T_{in} - T_{out})$$ where:

1. **State the problem:** Calculate the heat flow per hour through a brick and mortar wall 9 inches thick, 10 feet high, and 6 feet wide. The thermal conductivity coefficient is 50