Answer:
What will happen to Uk if you double the mass?
Explanation:
Uk = 0.5 * m * v²
You see that both m and v are variable, which means that both m and v can be any number. Regardless of the numbers you put in for m or v, the formula to calculate the kinetic energy (Uk) remains valid.
You could ask
1. What will happen to Uk if you double the mass?
2. What will happen to Uk if you double the velocity?
please see and understand(!) that the relationship between Uk an v² is indeed the velocity squared....
EXTRA
Uk = 0.5 * m * (v)²
Suppose the m = 3kg and velocity = 5 m/s
What is the Uk?
Well if you know the formula you can use your calculator to find out:
Uk = 0.5 * m * (v)²
Uk = 0.5 * 3 * (5)²
Uk = 0.5 * 3 * 25
Uk = 37.5 kgm/s²
Again you ask what will happen to Uk if you double the velocity?
At first it was 5 m/s and now it doubles, which means it now has that value *2
The new velocity is 5 *2 = 10 m/s
Uk = 0.5 * m * (v)²
Uk = 0.5 * 3 * (10)²
Uk = 0.5 * 3 * 100
Uk = 150 kgm/s²
150 = 4 * 37.5
So now you see that if you double your velocity, the Uk will be 2² = 4 times as big !
Answer: The percentage composition of nitrogen , hydrogen and oxygen is 22.2 % , 1.59 % and 76.2% respectively.
Explanation:
Percentage composition is defined as the ratio of mass of substance to the total mass in terms of percentage.
Percentage composition=
a) 
b) 
c) 
The percentage composition of nitrogen , hydrogen and oxygen is 22.2 % , 1.59 % and 76.2% respectively.
Answer:
0.0010m SO₄²⁻
Explanation:
The freezing point depression due the addition of a solute into a pure solvent follows the equation:
ΔT = Kf×m×i (1)
<em>Where ΔT are °C that freezing point decreases (273.15K - 272.47K = 0.68K = 0.68°C). Kf is the constant of freezing point depression (1.86°C/m), m is molality of the solution (0.1778m) and i is Van't Hoff factor.</em>
Van't Hoff factor could be understood as in how many one mole of the solute (sulfuric acid, H₂SO₄), is dissociated.
H₂SO₄ dissociates as follows:
H₂SO₄ → HSO₄⁻ + H⁺
HSO₄⁻ ⇄ SO₄²⁻ + H⁺
<em>Not all HSO₄⁻ dissociates.</em>
1 Mole of H₂SO₄ dissociates in 1 mole of H⁺+ 1 mole of HSO₄⁻ + X moles of SO₄²⁻= 2 + X
Replacing in (1):
0.68°C = 1.86°C/m×0.1778m×i
2.056 = i
Moles of SO₄²⁻ are 2.056 - 2 = 0.056moles SO₄²⁻.
If 1 mole has a concentration of 0.1778m, 0.056moles are:
0.056moles ₓ (0.1778m / 1mole) =
<h3>0.0010m SO₄²⁻</h3>
D shows the chemical reaction took place
