Can somebody help me with this please

A silver cube with an edge length of 2.38 cm and a gold cube with an edge length of 2.79 cm are both heated to 81.9 ∘C and place

never [62]

Answer:

The final temperature of the water when thermal equilibrium is reached is 23.54 ⁰C

Explanation:

Given data;

edge length of silver, a = 2.38 cm = 0.0238 m

edge length of gold, a = 2.79 cm = 0.0279 m

final temperature of silver, t = 81.9 ° C

final temperature of Gold, t = 81.9 ° C

initial temperature of water, t = 19.6 ° C

volume of water, v = 109.5 mL = 0.0001095 m³

Known data:

density gold 19300 kg/m³

density silver 10490 kg/m³

density water 1000 kg/m³

specific heat gold is 129 J/kgC

specific heat silver is 240 J/kgC

specific heat water is 4200 J/kgC

Calculated data

Apply Pythagoras theorem to determine the side of each cube;

Silver cube;

let L be the side of the silver cube

Taking the cross section of the cube (form a right angled triangle), the edge length forms the hypotenuse side.

L² + L² = 0.0238²

2L² = 0.0238²

L² = 0.0238² / 2

L² = 0.00028322

L = √0.00028322

L = 0.0168

Volume of cube = L³

Volume of the silver cube = (0.0168)³ = 4.742 x 10⁻⁶ m³

Gold cube;

let L be the side of the gold cube

L² + L² = 0.0279²

2L² = 0.0279²

L² = 0.0279² / 2

L² = 0.0003892

L = √0.0003892

L = 0.0197

Volume of cube = L³

Volume of the silver cube = (0.0197)³ = 7.645 x 10⁻⁶ m³

Mass of silver cube;

density = mass / volume

mass = density x volume

mass of silver cube = 10490 (kg/m³) x 4.742 x 10⁻⁶ (m³) = 0.0497 kg

Mass of Gold cube

mass of gold cube = 19300 (kg/m³) x 7.645 x 10⁻⁶ (m³) = 0.148 kg

Mass of water

mass of water = 1000 (kg/m³) x 0.0001095 (m³) = 0.1095 kg

Let the heat gained by cold water be Q₁

Let the heat lost by silver cube = Q₂

Let the heat lost by gold cube = Q₃

Let the final temperature of water = T

Q₁ = 0.1095 kg x 4200 J/kgC x (T–19.6)

Q₂ = 0.0497 kg x 240 J/kgC x (81.9–T)

Q₃ = 0.148 kg x 129 J/kgC x (81.9–T)

At thermal equilibrium;

Q₁ = Q₂ + Q₃

0.1095 x 4200 (T–19.6) = 0.0497 x 240 x (81.9–T) + 0.148 x 129 x (81.9–T)

459.9 (T–19.6) = 11.928 (81.9–T) + 19.092(81.9–T)

459.9T - 9014.04 = 976.9032 - 11.928T + 1563.6348 - 19.092T

459.9T + 11.928T + 19.092T = 9014.04 + 976.9032 + 1563.6348

490.92T = 11554.578

T = 11554.578 / 490.92

T = 23.54 ⁰C

Therefore, the final temperature of the water when thermal equilibrium is reached is 23.54 ⁰C

6 0

3 years ago

Item 3

svetoff [14.1K]

Answer:

Semiconductors are poor conductors at low temperatures, but their resistance decreases with increasing temperature.

Explanation:

A semiconductor can be defined as a crystalline solid substance that has its conductivity lying between that of a metal and an insulator, due to the effects of temperature or an addition of an impurity. Semiconductors are classified into two main categories;

1. Extrinsic semiconductor.

2. Intrinsic semiconductor.

The statement which best describes the electrical conductivity of metals and semiconductors is that semiconductors are poor conductors at low temperatures, but their resistance decreases with increasing temperature.

This ultimately implies that, semiconductors are typically an insulator (poor conductor) at low temperatures and a good conductor at high temperatures.

Additionally, conduction involves the transfer of electric charge or thermal energy due to the movement of particles. When the conduction relates to electric charge, it is known as electrical conduction while when it relates to thermal energy, it is known as heat conduction.

6 0

3 years ago

Who developed the concept that the total pressure of a mixture of gases is the sum of their partial pressures?.

victus00 [196]

Answer:

John Dalton

Explanation:

John Dalton developed the concept tittle: Dalton Law of Partial Pressure.

The formula is: Pt = Pa + Pb + Pc...... Pn

3 0

2 years ago

Draw and label the parts of a helium atom. Include the mass and charge of each subatomic particle.

mihalych1998 [28]

Explanation:

Helium is the second element on the periodic table.

Information about helium:

it belongs to group O on the periodic table
it is has an atomic number of 2
Helium exists naturally as gas and it is nonreactive.

To write an atom we use this format:

ₙᵇGˣ

G is the symbol of the atom

n is the atomic number

b is the mass number

x is the charge on the atom

Using the periodic table as guide

Symbol of helium is He

Atomic number of helium is 2

mass number of helium is 4

charge on helium atom is 0

⁴₂He

Every atom contains protons, neutrons and electrons;

Electrons are negatively charged. For a neutral atom, the number of electrons is the same as that of protons.

Protons are positively charge particles in an atom. The atomic number is the number of protons in an atom.

neutrons do not have charges.

Helium has:

Number of protons = 2

Number of electrons = 2

Number of neutrons = 2

Mass of each subatomic particle:

1 electron = 9.11 x 10⁻³¹kg

2 electrons = 1.82 x 10⁻³⁰kg

Protons and neutrons have the same mass:

1 proton = 1.67 x 10⁻²⁷kg

2 protons = 3.34 x 10⁻²⁷kg

2 neutrons = 3.34 x 10⁻²⁷kg

Learn more:

helium brainly.com/question/2439349

#learnwithBrainly

4 0

3 years ago

HELPPPPP MMMMEEEEEEEE

Scilla [17]

Rr - Round eyes. the two alleles are R and r, and if R is dominant, the phenotype will be round

7 0

3 years ago

Read 2 more answers