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stealth61 [152]

3 years ago

13

what is the geocentric model of stars and planets? a.) the belief that stars and planets revolve around the earth b.) the belief

that planets revolve around the stars c.) the belief that planets and the moon revolve around earth d.) the belief that stars and planets revolve around the sun

1 answer:

amid [387]3 years ago

7 0

a.) the belief that stars and planets revolve around the earth

Explanation:

The geocentric model of stars and planets is the belief that stars and planets revolves around the earth.

The model places the earth at the center of the system.

Geo - earth ; centric - center
This was the original school of thought about the way the earth relates to other bodies in the universe.
This model was replaced by the heliocentric universe in which stars are at the center and the planets revolves round them.
The idea was put forward by Nicola Copernicus

learn more:

Energy of the sun brainly.com/question/1140127

#learnwithBrainly

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Agata [3.3K]

1. B- it can cause cirrhosis
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3. A- admit to having a problem with alcohol
4. D- binge-drinking
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7 0

3 years ago

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From your ____ chest to your___ shoulders you must have been wearing

natita [175]

Sorry I don’t know the exact answer

7 0

2 years ago

An object is located 70 cm from a concave mirror with a focal length of 15 cm. What is the image

Stels [109]

(a) The distance of the image formed by the concave mirror is 19.1 cm.

(b) The image formed is diminished and real.

<h3>Image distance </h3>

The distance of the image formed by the concave mirror is calculated as follows;

1/f = 1/v + 1/u

1/v = 1/f - 1/u

1/v = 1/15 - 1/70

1/v = 0.05238

v = 1/0.05238

v = 19.1 cm

The image distance is smaller than object distance, thus the image formed is diminished and real.

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5 0

1 year ago

A loaded 375 kg toboggan is traveling on smooth horizontal snow at 4.50 m/s when it suddenly comes to a rough region. The region

zmey [24]

Answer:

a) The average friction force exerted on the toboggan is 653.125 newtons, b) The rough region reduced the kinetic energy of the toboggan in 92.889 %, c) The speed of the toboggan is reduced in 73.333 %.

Explanation:

a) Given the existence of non-conservative forces (friction between toboggan and ground), the motion must be modelled by means of the Principle of Energy Conservation and the Work-Energy Theorem, since toboggan decrease its speed (associated with due to the action of friction. Changes in gravitational potential energy can be neglected due to the inclination of the ground. Then:

$K_{1} = K_{2} + W_{f}$

Where:

$K_{1}$ , $K_{2}$ are the initial and final translational kinetic energies of the tobbogan, measured in joules.

$W_{f}$ - Dissipated work due to friction, measured in joules.

By applying definitions of translation kinetic energy and work, the expression described above is now expanded and simplified:

$f\cdot \Delta s = \frac{1}{2}\cdot m \cdot (v_{1}^{2}-v_{2}^{2})$

Where:

$f$ - Friction force, measured in newtons.

$\Delta s$ - Distance travelled by the toboggan in the rough region, measured in meters.

$m$ - Mass of the toboggan, measured in kilograms.

$v_{1}$ , $v_{2}$ - Initial and final speed of the toboggan, measured in meters per second.

The friction force is cleared:

$f = \frac{m\cdot (v_{1}^{2}-v_{2}^{2})}{2\cdot \Delta s}$

If $m = 375\,kg$ , $v_{1} = 4.50\,\frac{m}{s}$ , $v_{2} = 1.20\,\frac{m}{s}$ and $\Delta s = 5.40 \,m$ , then:

$f = \frac{(375\,kg)\cdot \left[\left(4.50\,\frac{m}{s} \right)^{2}-\left(1.20\,\frac{m}{s}\right)^{2}\right]}{2\cdot (5.40\,m)}$

$f = 653.125\,N$

The average friction force exerted on the toboggan is 653.125 newtons.

b) The percentage lost by the kinetic energy of the tobbogan due to friction is given by the following expression, which is expanded and simplified afterwards:

$\% K_{loss} = \frac{K_{1}-K_{2}}{K_{1}}\times 100\,\%$

$\% K_{loss} = \left(1-\frac{K_{2}}{K_{1}} \right)\times 100\,\%$

$\% K_{loss} = \left(1-\frac{\frac{1}{2}\cdot m \cdot v_{2}^{2}}{\frac{1}{2}\cdot m \cdot v_{1}^{2}} \right)\times 100\,\%$

$\% K_{loss} = \left(1-\frac{v_{2}^{2}}{v_{1}^{2}} \right)\times 100\,\%$

$\%K_{loss} = \left[1-\left(\frac{v_{2}}{v_{1}}\right)^{2} \right]\times 100\,\%$

If $v_{1} = 4.50\,\frac{m}{s}$ and $v_{2} = 1.20\,\frac{m}{s}$ , then:

$\%K_{loss} = \left[1-\left(\frac{1.20\,\frac{m}{s} }{4.50\,\frac{m}{s} }\right)^{2} \right]\times 100\,\%$

$\%K_{loss} = 92.889\,\%$

The rough region reduced the kinetic energy of the toboggan in 92.889 %.

c) The percentage lost by the speed of the tobbogan due to friction is given by the following expression:

$\% v_{loss} = \frac{v_{1}-v_{2}}{v_{1}}\times 100\,\%$

$\% v_{loss} = \left(1-\frac{v_{2}}{v_{1}} \right)\times 100\,\%$

If $v_{1} = 4.50\,\frac{m}{s}$ and $v_{2} = 1.20\,\frac{m}{s}$ , then:

$\% v_{loss} = \left(1-\frac{1.20\,\frac{m}{s} }{4.50\,\frac{m}{s} } \right)\times 100\,\%$

$\%v_{loss} = 73.333\,\%$

The speed of the toboggan is reduced in 73.333 %.

5 0

2 years ago

Explain each of the following phenomena and how they extend our understanding of genetics from the work done by Gregor Mendel an

Korolek [52]

Answer:

Incomplete Dominance: In this case, the 3rd different phenotype is created by the heterozygous(CwCr) (for example, pink)

Co-Dominance: the heterozygous is observed to show both the homozygous conditions (for example the blood type iAiB shows both A and B carbohydrates)

Multiple alleles: This is when a gene has over 2 alleles (i.e. blood has ia ib i)

Polygenic inheritance: This is when over two different gene leads to the expression of a trait.

Pleiotropy: This is the when a gene shows several effects on an organism.

Epistasis: This is when more than one gene have strong control on the expression of a trait (for example, E/e allele creates pigments)

Sex-linkage: This refers to the genes found in sex chromosomes

Gene Linkage: These are the genes situated in a similar chromosome.

Explanation:

Incomplete Dominance: In this case, the 3rd different phenotype is created by the heterozygous(CwCr) (for example, pink)

Co-Dominance: the heterozygous is observed to show both the homozygous conditions (for example the blood type iAiB shows both A and B carbohydrates)

Multiple alleles: This is when a gene has over 2 alleles (i.e. blood has ia ib i)

Polygenic inheritance: This is when over two different gene leads to the expression of a trait.

Pleiotropy: This is the when a gene shows several effects on an organism.

Epistasis: This is when more than one gene have strong control on the expression of a trait (for example, E/e allele creates pigments)

Sex-linkage: This refers to the genes found in sex chromosomes

Gene Linkage: These are the genes situated in a similar chromosome.

7 0

2 years ago