All categories

2 years ago

How much thermal energy is needed to raise the temperature of 15kg gold from 45⁰ C up to 80⁰ C

Engineering

1 answer:

Levart [38]2 years ago

6 0

Answer:

68.25 kJ

Explanation:

The thermal energy Q required to raise the temperature of 15kg gold from 45⁰ C up to 80⁰ C is Q = mcΔθ where m = mass of gold = 15 kg, c = specific heat capacity of gold = 130 J/kg°C and Δθ = temperature change = θ₂ - θ₁ where θ₁ = 45 °C and θ₂ = 80 °C

So, Q = mcΔθ = mc(θ₂ - θ₁)

= 15 kg × 130 J/kg°C × (80 °C - 45 °C)

= 1950 J/°C × 35 °C

= 68,250 J

= 68.25 kJ

You might be interested in

Estimate the quantity of soil to be excavated from the borrow pit

Serggg [28]

Answer

1056

Explanation:

for example

A soil is to be excavated from a borrow pit which has a density of 1.75g/cc and water content of 12%. The G is 2.7 the soil is compacted to that water content of 18% and dry density of 1.65g/cc. for 1000 m3 of soil used in fill estimate

Quantity of soil to be excavated from pit in m3

6 0

2 years ago

In an experiment, the local heat transfer over a flat plate were correlated in the form of local Nusselt number as expressed by

Stells [14]

Answer:

$\dfrac{\bar{h}}{h}=\dfrac{5}{4}$

Explanation:

Given that

$Nu_x=0.035Re_x^{0.8} Pr^{1/3}$

We know that

Rex=ρvx/μ

$Nu_x=0.035Re_x^{0.8} Pr^{1/3}$

$Nu_x=0.035\times\left(\dfrac{\rho vx}{\mu}\right)^{0.8}Pr^{1/3}$

All other quantities are constant only x is a variable in the above equation .so lets take all other quantities as a constant C

$Nu_x=C.x^{0.8}=C.x^{4/5}$

We also know that

Nux=hx/K

$C.x^{4/5}=\dfrac{hx}{k}$

m is the constant

$h=mx^{-1/5}$

This is local heat transfer coefficient

The average value of h given as

$\bar{h}=\dfrac{\int_{0}^{L}hdx}{L}$

$\bar{h}=\dfrac{5m}{4}\times\dfrac{L^{4/5}}{L}$

$\bar{h}=\dfrac{5m}{4}L^{-1/5}$ ---------1

The value of local heat transfer coefficient at x=L

$h=mx^{-1/5}$

$h=mL^{-1/5}$ -----------2

From 1 and 2 we can say that

$\dfrac{\bar{h}}{h}=\dfrac{5}{4}$

8 0

3 years ago

11. Ten bagels is what percentage of a dozen bagels?

IRINA_888 [86]

Answer:

the answer is d 83.3%

Explanation:

3 0

2 years ago

What are some common work contexts for Licensing Examiners and Inspectors? Select four options.

Akimi4 [234]

According to O*NET, the common work contexts for Licensing Examiners and Inspectors include:

Telephone
Face-to-face discussions
Contact with others
Importance of being exact or accurate.

O*NET is an acronym for occupational information network and it refers to a free resource center or online database that is updated from time to time with several occupational definitions, so as to help the following categories of people understand the current work situation in the United States of America:

Workforce development professionals

Students

Human resource (HR) managers

Job seekers

Business firms

On O*NET, work contexts are typically used to describe the physical and social elements that are common to a particular profession or occupational work. Also, the less common work contexts are listed toward the bottom while common work contexts are listed toward the top.

According to O*NET, the common work contexts for Licensing Examiners and Inspectors include:

1. Telephone

2. Face-to-face discussions

3. Contact with others

4. Importance of being exact or accurate.

Read more on work contexts here: brainly.com/question/22826220

6 0

2 years ago

Read 2 more answers

List and explain 4 factors you need to observe while stick welding to make a good “consistent” bead

ch4aika [34]

Answer:I don’t know this one

Explanation:

5 0

3 years ago

How much thermal energy is needed to raise the temperature of 15kg gold from 45⁰ C up to 80⁰ C​

How much thermal energy is needed to raise the temperature of 15kg gold from 45⁰ C up to 80⁰ C