: Which of the following are the requirements for successful animal reproduction?

Anna is conducting an experiment to determine how weather affects cell phone reception. She is trying to decide the best way to

aev [14]

Answer:

D. Test a cell phone's reception in the exact same location under various atmospheric conditions

Explanation:

Components of an experiment:

Independent variable:

A manipulated variable, in an experiment or study, whose presence or degree incurs a change in the dependent variable.

Dependent variable:

A variable which is being studied in the experiment and is supposed to change with respect to the independent variable.

Control variable:

Control variable includes the variables which are of no concern in the experiment and must be constant so that they do not interfere with the results of the experiment. Change in control variable might affect the results of an experiment.

In Anna's experiment, the independent variable is the atmospheric conditions. The dependent variable is cell phone reception that will change according to the atmospheric conditions. All other things related to the experiment are control variables like cellphone, location of the cell phone. Both of these must stay constant to collect the best data.

Hence, the best option is D.

4 0

3 years ago

Usain Bolt, a Jamaican sprinter, holds the Olympic and world records for the 100-m and 200-m dash, which he

stellarik [79]

Answer: 10.36m/s

How? Just divide 200m by 19.3 and you will get how fast he ran per m/s

6 0

3 years ago

The nucleus of an atom can be modeled as several protons and neutrons closely packed together. Each particle has a mass of 1.67

Lady bird [3.3K]

Explanation:

The nucleus of an atom can be modeled as several protons and neutrons closely packed together.

Mass of the particle, $m=1.67\times 10^{-27}\ kg$

Radius of the particle, $R=10^{-15}\ m$

(a) The density of the nucleus of an atom is given by mass per unit area of the particle. Mathematically, it is given by :

$d=\dfrac{m}{V}$ , V is the volume of the particle

$d=\dfrac{m}{(4/3)\pi r^3}$

$d=\dfrac{1.67\times 10^{-27}}{(4/3)\pi (10^{-15})^3}$

$d=3.98\times 10^{17}\ kg/m^3$

So, the density of the nucleus of an atom is $3.98\times 10^{17}\ kg/m^3$ .

(b) Density of iron, $d'=7874\ kg/m^3$

Taking ratio of the density of nucleus of an atom and the density of iron as :

$\dfrac{d}{d'}=\dfrac{3.98\times 10^{17}}{7874}$

$\dfrac{d}{d'}=5.05\times 10^{13}$

$d=5.05\times 10^{13}\ d'$

So, the density of the nucleus of an atom is $5.05\times 10^{13}$ times greater than the density of iron. Hence, this is the required solution.

7 0

4 years ago

Are there Universes outside if this one?

Kay [80]

There may be alternate and/or parallel universes outside of ours, but we cannot make sure. Since "space" is always expanding and never-ending, they may not be. It depends on how you look at the world and the facts and opinions of the world.

6 0

3 years ago

Explain how the sun's position in the sky would change the direction of your shadow if you were to stand in the same place all d

rusak2 [61]

Shadows move in the opposite direction to the sun. Since the sun changes position throughout the day this alters the direction and position of your shadow

4 0

3 years ago