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3 years ago

A sample that is treated exactly like the other experimental groups except that the variable is not applied to it is a(n) _____.

1 answer:

7 0

This is a "control" - answer c).

You always need a control in an experiment, otherwise you don't know what influenced the changes. Imagine you make children eat more vegetables and they grow - do you know if it's due to vegetables or not? You need to have another group that eats normal amounts of vegetables to compare this.
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Our best evidence and theoretical calculations indicate that the solar system began with a giant spinning system of gas and dust

Anna35 [415]

Answer:

Solar nebula.

Explanation:

A planet can be defined as a large celestial body having sufficient mass to allow for self-gravity and make it assume a nearly circular shape (hydrostatic equilibrium), revolves in an orbit around the Sun in the solar system and has a cleared neighborhood.

Basically, the planets are divided into two (2) main categories and these includes;

1. Outer planets: these planets are beyond the asteroid belt and comprises of jupiter, saturn, uranus and neptune, from left to right of the solar system.

2. Inner planets: these planets are the closest to the sun and comprises of mercury, venus, earth and mars.

These outer planets are made mostly of gases (hydrogen and helium) causing them to be less dense than the solid inner planets. These gases are generally known to be less dense in terms of physical properties.

Some examples of the planet found in the solar system are Mars, Venus, Earth, Mercury, Neptune, Jupiter, Saturn, Uranus, Pluto, etc.

Scientists have been able to understand and discover that, gravity pulled materials (low-density cloud of interstellar gas and dust known as a nebula) together forming the planetary bodies in our solar system.

A dark nebula can be defined as an interstellar cloud that is so dense as a result of high concentration of gas and dust and as such it obscures the visible wavelengths of light from stars behind it, thus appearing completely opaque (dark patch) in front of a bright emission nebula or in regions having plenty stars.

The characteristics of a nebulae are;

I. It contain hydrogen.

II. Clouds of gas and dust

III. It is needed to create a star.

8 0

3 years ago

Why is the efficiency of a machine always less than 100 percent? The work input is too small. It cannot have an IMA greater than

kozerog [31]

Answer:

Some work input is lost to friction

Explanation:

The efficiency of a machine is defined as:

$\eta = \frac{W_{out}}{W_{in}}$ (1)

where

$W_{out}$ is the work output

$W_{in}$ is the work input

Due to the law of conservation of energy, the work output can never be larger than the work input (because energy cannot be created). Moreover, in real machines part of the work input is lost due to the presence of frictions: as a result, part of the energy in input is converted into thermal energy or other forms of energy, and so the work output is smaller than the work input, and so the ratio (1) becomes less than 1, and so the efficiency is less than 100%.

3 0

3 years ago

Read 2 more answers

Mrs. Nogaki uses constant force to push a Costco shoping cart down the long store

Liono4ka [1.6K]

Figure B. The second option.

7 0

3 years ago

Lottery balls are thrown into a hopper and are set into motion by air forced through the container. each ball has a mass of 0.00

Marina CMI [18]

In this three body system total kinetic energy remains constant:
$E_{k} = constant =0.0268 J$

$E_{k} = E_{k1}+ E_{k2}+ E_{k3}$
If we assume that upwards movement is positive and downwards movement is negative the formula is:
$E_{k} = E_{k1}- E_{k2}+ E_{k3}$

Formula for kinetic energy is:
$E_{k} = \frac{m v^{2} }{2}$

Now we have:
$E_{k} = \frac{m v_{1} ^{2} }{2} -\frac{m v_{2} ^{2} }{2} +\frac{m v_{3} ^{2} }{2} \\ E_{k} = \frac{m}{2} (v_{1} ^{2}-v_{2} ^{2}+v_{3} ^{2}) \\ \\ 0.0268= \frac{0.0044}{2} (1.3 ^{2}-1.66^{2}+v_{3} ^{2}) \\ \\ 0.0536=0.0022(1.69-2.7556+v_{3} ^{2}) \\ \\ v_{3} ^{2}=25.43 \\ \\ v_{3} =+-5.04$

We got two solutions: positive and negative. The speed is 5.04 m/s and direction can be upwards and downwards.

3 0

3 years ago

if the distance moved by the effort is greater than the distance moved by the load, the machine is speed multiplier. TRUE/FALSE

just olya [345]

Answer: TRUE

Explanation: I did it before

4 0

2 years ago