Physics Answers

A perfect gas has a molar mass of 26 kg/kmol and a value of 𝛾 = 1.26. Calculate the heat rejected when unit mass of the gas is contained in a rigid vessel at 3 bar and 315℃, and is then cooled until the pressure falls to 1.5 bar. Assuming that 𝐶𝑣 = 1.229 𝑘𝐽/𝑘𝑔𝐾 and 𝐶𝑝 = 1.548 𝑘𝐽/𝑘𝑔𝐾. 

Why is it important to position the JWST behind the Earth?

how would you relate alchemy to synthesis of new elements

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A voltmeter which is connected across a lightbulb in a circuit, reads 2V.  Consider the following: 

For every one coulomb of charge flowing through the bulb: 

1. 2J of heat and light is liberated 
2. The potential energy decreases with 2J 
3. The potential energy increases with 2J 

1. i and ii 
2. i and iii 
3. ii and iii 
4. i, ii, and iii 

The magnitude of the electric current in a circuit will definitely increase if 

1. more cells are in parallel 
2. the resistors are connected in parallel 
3. the cells are connected in parallel and the resistors in series 
4. Both the cells and resistors are connected in parallel 

neutron stars are some of the densest objects in universe. The form during supernova explosions and very small compared to other astronomical objects you can assume 5*10¹⁷kg/m³ as the average density of a neutron star The earth has a total mass of about 5.97*10²⁴kg what would be the diameter of the earth if it had the density of a neutron star

A block of m1=20.0 kg is placed on a plane incline at angle

α=37.1° and is connected to a second hanging block with mass

m2 by a cord passing over a small, frictionless pulley. The

coefficient of kinetic friction between the plane and the block is

0.30.

Two equal positive charges q1 q2 = 4.0 μC are located at (1.20 m, 0) and (-1.20 m, 0), = respectively. What are the magnitude and direction of the total electric force that q1 and q2 exerts on a third charge q3= 7.0 μC located at (0, -0.50 m) ?

How much charge is on each plate of a 4.00-µF capacitor when it is connected

to a 12.0-V battery (? (b) If this same capacitor is connected to a 1.50-V

battery, what charge is stored?

A capacitor is constructed from two conductive metal plates 30cm x 50cm

which are spaced 6mm apart from each other, and uses dry air as its only

dielectric material. Calculate the capacitance of the capacitor. (0.221nF).