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Scorpion4ik [409]
3 years ago
9

What makes a model not useful?

Physics
1 answer:
lina2011 [118]3 years ago
8 0
Answer is b hope this helps
You might be interested in
Question 23
bonufazy [111]

If the gymnast mass were doubled, her height (h) from the top of the board would be as follows,

с  Stay the same

Explanation:

  • The Mass of an object or body does not affect the acceleration due to gravity in any kind of way.
  • Light weight objects accelerate more slowly than the heavy objects because when the forces other than the gravity also plays a major role.
  • Mass increases of a body when an object has higher velocity or the speed.
  • The greater the force of gravity, it would give a direct impact on the object's acceleration; thus considering only a force, the heavier the object is, it would accelerate faster. But an acceleration depends upon the two factors which are  force and mass.
  • Newton's second law of motion states that the acceleration of an object is dependent upon the two factors which are, the net force of an object and the mass of the object.

3 0
3 years ago
The volumes of the block is 10,500 mL and density is 8.52 g/mL. Find the block's mass Don't forget units and a space
Schach [20]

Answer:

<h2>89,460 g</h2>

Explanation:

The mass of a substance when given the density and volume can be found by using the formula

mass = Density × volume

From the question we have

mass = 8.52 × 10,500

We have the final answer as

<h3>89,460 g</h3>

Hope this helps you

3 0
2 years ago
One of China's cement factories has become more energy efficient by ________. a. using the extra gas and heat from the kilns to
OleMash [197]

Answer:

a. using the extra gas and heat from the kilns to generate electricity

Explanation:

Wiley Online Library

Energy Science & EngineeringVolume 5, Issue 2

Research Article Open Access

The generation of power from a cement kiln waste gases: a case study of a plant in Kenya

Stanley Ngari Irungu Peter Muchiri Jean Bosco Byiringiro

First published: 01 April 2017

https://doi.org/10.1002/ese3.153

Citations: 1

No funding information provided.

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Abstract

The cement production process is energy intensive both in terms of the thermal energy (firing the kiln, drying and De carbonation) and electrical energy for driving the numerous drives within the process line. The average specific power consumption of the case study plant was 111 kWh/ton of cement with an average peak demand of 9.7 MW. The high cost of electric power at 0.14 USD/kWh results in very high cost of production that significantly lowers the company's profit margin and limits its competitive advantage. The generation of electrical power from waste heat recovery would reduce the electricity power bill through partially substituting the power procured from the national grid. This research evaluated the potential that the plant has for generating electrical power from the hot waste gases vented into the atmosphere and it was found that the plant has the potential to generate 3.4 MWh of electrical power. This results to a net potential to generate 2.89 MWh of electrical power after factoring in the auxiliary power consumption by Waste heat recovery plant system at 15%. This ultimately gave a reduction of 33% in the electricity power bill of the case study plant. The paper recommends the installation of a steam rankine cycle for the power generating plant. In this work the authors designed the steam boilers for the waste heat recovery plant for conversion of thermal energy to electrical energy, selected a commercial steam turbine and evaluated its economic feasibility and established that the designed plant would have a simple payback period of 2.7 years.

Introduction

The cement manufacturing process is an energy intensive industry, both in terms of thermal and electrical energy. The cost of energy keeps on fluctuating and this negatively impact on the manufacturing cost and eventually lowers the competitiveness and profitability of the cement industry. The energy costs in a cement industry account for about 26% of the total manufacturing cost of cement which is in the form of electrical energy accounting for 25% of the input energy and 75% is thermal energy 1. Furthermore, the sources of thermal energy utilized in the cement industry are mostly nonrenewable and this necessitates deep consideration of energy conservation to guarantee sustainability.

The case study plant suffers financial loss as a result of higher per unit cost of power from the grid and the poor reliability of the supply. The poor reliability of supply negatively affects the kiln operations (the heart of operations) as a result of the sensitivity of the process to power quality resulting in high set up costs. This significantly raises the cost of production for the case study plant and eventually results in the loss of her competitive advantage.

The generation of Power from the cement kiln Waste Heat gases is an energy saving opportunity and it entails the recovery of the heat energy contained in the waste gases that are emitted into the atmosphere from the cement kiln. According to 2, the generation of Power from kiln Waste Heat Recovery is about conversion of the waste heat from the clinkering process into useful electrical energy. Cogeneration of power is achieved by utilizing this waste heat streams from the preheater and the cooler, passing the waste gases through boilers, which in turn generate steam which is used to turn/run turbines to generate electricity

7 0
3 years ago
What is my name if it starts with a then m then a then r then y?
Ierofanga [76]

Answer:

Amary

Explanation:

?

8 0
3 years ago
Read 2 more answers
Danny's mother believes her own fear of big dogs may have led to his phobia. This explanation is pointing to ______________.
matrenka [14]
<h2><u>Answer:</u></h2>

Cynophobia

<h3><u>Explanation:</u></h3>

Cynophobia originates from the Greek words that signify "dog" (cyno) and "fear" (phobis). An individual who has cynophobia encounters a dread of mutts that is both unreasonable and tenacious. It's something beyond feeling of scaredness whether a dog is barking or an individual is around dogs.

An individual who has cynophobia encounters a dread of dogs that is both silly and constant. Explicit fears, similar to cynophobia, influence somewhere in the range of 7 to 9 percent of the populace. They're regular enough that they're formally perceived in the Diagnostic and Statistical Manual of Mental Disorders,

6 0
3 years ago
Read 2 more answers
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