Answer:
The average velocity of the airplane for this trip is 1684.21 km/h
Explanation:
Average velocity is the rate of change of displacement with time. That is,
Average velocity = 
= Δx / Δt = 
Now we will calculate the time taken by the airplane for the first motion before it encounters a wind.
From,
Velocity = 
Time = 
Therefore, Time = 
Time = 2.1h
This is the time taken before the airplane encounters a wind.
Hence, t1 = 2.1h
Now, For the time taken by the airplane when it encounters a wind
Also from,
Velocity =
Time =
Therefore, Time = 
Time = 1.625h
Hence, t2 = 1.625h
Now, to calculate the average velocity
Average velocity =
x1= 2100, x2= 1300, t1= 2.1h and t2= 1.625h
Hence, Average velocity = 
Average velocity = 1684.21 km/h
As with the properties of a substance, the changes that substances undergo can be classified as either physical or chemical. During physical changes a substance changes its physical appearance, but not its composition. The evaporation of water is a physical change.
(I searched that up but here’s an explanation with my own words that you can use):
Change in matter can be classified as a physical change as well as a chemical change due to the properties of substance. A physical change changes substance within its appearance but not its composition. For an example: The evaporation of water is a physical change.
There you go hopefully that helped
Answer:
0.0702J/g°C the specific heat capacity of the metal.
Explanation:m
where,
Q = heat absorbed by metal = 186.75 J
= Mass of metal= 19 g
= Initial temperature of metal = 
=Final temperature of metal = 
= specific heat of metal= ?
0.0702J/g°C the specific heat capacity of the metal.
Answer is: lithium is the least reactive and potassium is the most reactive of the three alkali elements.
<span>The </span>reactivity<span> of the alkali metals increases down the group because one valence electron (I group of Periodic system of elements) is farther away from nucleus and attraction force between electron and proton is weaker.</span>
Answer : The pH of the solution is, 3.41
Explanation :
First we have to calculate the moles of 
.
Now we have to calculate the value of 
.
The expression used for the calculation of is,
Now put the value of 
in this expression, we get:
The reaction will be:
Initial moles 0.375 0.100 0.375
At eqm. (0.375-0.100) 0 (0.375+0.100)
= 0.275 = 0.475
Now we have to calculate the pH of solution.
Using Henderson Hesselbach equation :
![pH=pK_a+\log \frac{[Salt]}{[Acid]}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%20%5Cfrac%7B%5BSalt%5D%7D%7B%5BAcid%5D%7D)
![pH=pK_a+\log \frac{[F^-]}{[HF]}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%20%5Cfrac%7B%5BF%5E-%5D%7D%7B%5BHF%5D%7D)
Now put all the given values in this expression, we get:
![pH=3.17+\log [\frac{(\frac{0.475}{1.50})}{(\frac{0.275}{1.50})}]](https://tex.z-dn.net/?f=pH%3D3.17%2B%5Clog%20%5B%5Cfrac%7B%28%5Cfrac%7B0.475%7D%7B1.50%7D%29%7D%7B%28%5Cfrac%7B0.275%7D%7B1.50%7D%29%7D%5D)
Thus, the pH of the solution is, 3.41
