Answer:

Explanation:
<h3><u>Given data:</u></h3>
Acceleration = a = 0.4 m/s²
Initial Speed =
= 20 m/s
Final Speed =
= 40 m/s
<h3><u>Required:</u></h3>
Time = t = ?
<h3><u>Formula:</u></h3>

<h3><u>Solution:</u></h3>
Rearranging formula for t
![\displaystyle t =\frac{V_f-V_i}{a} \\\\t = \frac{40-20}{0.4} \\\\t = \frac{20}{0.4} \\\\\boxed{t = 50 \ seconds}\\\\\rule[225]{225}{2}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20t%20%3D%5Cfrac%7BV_f-V_i%7D%7Ba%7D%20%5C%5C%5C%5Ct%20%3D%20%5Cfrac%7B40-20%7D%7B0.4%7D%20%5C%5C%5C%5Ct%20%3D%20%5Cfrac%7B20%7D%7B0.4%7D%20%5C%5C%5C%5C%5Cboxed%7Bt%20%3D%2050%20%5C%20seconds%7D%5C%5C%5C%5C%5Crule%5B225%5D%7B225%7D%7B2%7D)
Answer:
Temperature
Explanation:
Here the factor that Elle is controlling is the temperature. So temperature here is the independent variable and the dependent variable is the rate of evaporation of water. Independent variable is controlled during the experiment setup and the outcome of the dependent variable depends on the independent variable.
Answer:
100 J of energy are needed to heat the copper from 20∘C to 80∘C .
Answer:
See explanation
Explanation:
The valence electrons are electrons found on the valence (outermost) shell of an atom.
When an atoms form compounds, there is an exchange of valence electrons between the atoms of one element and the atoms of another element.
Let us consider a typical example, sodium has one valence electron and chlorine has seven valence electrons. This means that chlorine needs one electron to complete its octet while sodium needs to release one electron in order to attain the octet structure.
So, sodium gives out its one electron and becomes a stable sodium ion and chlorine accepts that electron and becomes a stable chloride ion. This is how the compound sodium chloride is formed.