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3 years ago

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Physics

1 answer:

meriva3 years ago

6 0

Answer: i think c

Explanation:QA: “What is ordinary glass made of ?”

Glass is mostly silica, or silicon dioxide, present as quartz in many types of sand. Pure silica forms a highly transparent glass, but has a very high melting or softening temperature, around 1700°C. Even at such high temperatures it is highly viscous and difficult to work. Its use is largely confined to applications requiring high transparency to ultra-violet and infra-red radiation, stability at elevated temperatures or low thermal expansion coefficient.

“Ordinary glass” windows and drinking vessels are typically made from soda-lime glass, containing silica with around 25% sodium, calcium and other oxides, which together reduce the softening temperature to roughly 500–600°C

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An 880n box is pushed across a level floor for a distance of 5.0m with a force of 440n. how much work was done on the box

Simora [160]

W=Fd, F=440N, d=5m. 5x440=2,200J of work

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3 years ago

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The Democratic Party today is generally considered more liberal than the Republican Party because its members and elected offici

m_a_m_a [10]

Today, the House Democratic caucus is composed mostly of progressives and centrists, with a smaller minority of conservative Democrats. The party's philosophy of modern liberalism advocates social and economic equality, along with the welfare state. It seeks to provide government intervention and regulation in the economy.

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3 years ago

Light emitting diode (LEDs) light bulbs have become required in recent years, but do they make financial sense? Suppose a typica

kogti [31]

Answer:

The break even cost is $0.0063825

Explanation:

Break-even cost is the amount of money, or change in value, which equates to the amount at which an asset must be sold to equal the cost of acquiring it. For easier understanding it can be thought the amount of money for which a product or service must be sold to cover the costs of manufacturing or providing it.

Wattage = W

Cost per kilo watt hour = C

Number of hours per year = H

Price per bulb/CFL = P

Discount rate = 11%

Life of bulb = 2 years

Price of bulb = $0.39

Wattage consumption of bulb per hours = 60

Life of CFL = 24 years

Price of CFL = $3.10

Wattage consumption of CFL per hour = 15

Calculate the Equated Annual Cost (EAC) of bulb

EAC = {- P - (W/1000 x H x C) x (PVIFA 11%, 2years)}/ (PVIFA 11%, 2years)

PVIFA 11%, 2years = Annuity PV Factor = [1 – {(1 + r)^(-n)}]/r, where r is the rate per period and n is the number per periods

PVIFA 11%, 2 years = [1 – {(1 + 0.11)^(-2)}]/0.11 = 1.712523 (for 2 years)

PVIFA 11%, 24 years = [1 – {(1 + 0.11)^(-24)}]/0.11 = 8.348136 (for 2 years)

Calculate the EAC of bulb

EAC = {- P - (W/1000 x H x C) x (PVIFA 11%, 2 years)}/ (PVIFA 11%, 2 years)

EAC = {- 0.39 - (60/1000 x H x C) x (1.712523)}/ (1.712523)

EAC = {-0.39 – (51.37570 x C)}/ 1.712523, consider this equation 1

Calculate the EAC of CFL

EAC = {- P - (W/1000 x H x C) x (PVIFA 11%, 24 years)}/ (PVIFA 11%, 24 years)

EAC = {- 3.10 - (15/1000 x 500 x C) x (8.348136)}/ (8.348136)

EAC = {-3.10 – (62.61102 x C)}/8.348137, consider this equation 2

Equate 1 and 2 to find the amount of C

{-0.39 – (51.37570 x C)}/ 1.712523 = {-3.10 – (62.61102 x C)}/8.348137

{-0.39 – (51.37570 x C) x 8.348137} = {-3.10 – (62.61102 x C) x 1.712523}

C = $0.0063825

Thus, the break- even cost per kilo – watt is $0.0063825

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3 years ago

Electromagnets can be used to lock doors. How could an engineer increase the strength of an electromagnetic lock? Check all that

ddd [48]

The answer should be A

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3 years ago

During which phase of the moon do neap tides occur?

Fynjy0 [20]

Answer:

First Quarter and Third Quarter.

Explanation:

Tides are formed as a consequence of the differentiation of gravity due to the Moon across to the Earth sphere.

Since gravity variates with the distance:

$F = G\frac{m1\cdot m2}{r^{2}}$ (1)

Where m1 and m2 are the masses of the two objects that are interacting and r is the distance between them.

For example, seeing the image below, point A is closer to the Moon than point b, and at the same time the center of mass of the Earth will feel more attracted to the Moon than point B. Therefore, that creates a tidal bulge in point A and point B.

When the Sun and the Moon are alight with respect to the Earth, then the Sun tidal force contributes to the tidal force of the Moon over the Earth. That makes the high tides even higher (spring tides).

However, when the Sun is not in the same line than the Moon (the Moon is at 90° with respect to the Sun), then the low tides are higher and the high tides are lower. That scenario is known as neap tides.

Therefore, that happens when the Moon is at First Quarter and Third Quarter.

4 0

3 years ago

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