A positive acceleration indicates that the object sped up. This means that if you compare the first speed to the second, the second speed should be higher.
A negative acceleration indicates that the object has slowed down. This means that if you compare the first speed to the second, the second speed should be lower.
If an acceleration is 0, it means that it neither slowed down nor sped up.
Now let us analyze your problem by listing down the speed and the time:
At noon: 4 mi/hr
12:30 : 6 mi/hr
2:30 : 2 mi/hr
From noon to 12:30, you will notice that there is an increase in speed. This means that Tommy had a positive acceleration. (Rules out D.)
From 12:30 to 2:30, there is a decrease in speed. This would indicate that Tommy had a negative acceleration. (Rules out C.)
No speed was the same, so acceleration was never 0. (Rules out A.)
From the assumptions above, we can now deduce that the answer is B.
The empirical formula : C₂Cl₇
The molecular formula : C₁₀Cl₃₅
<h3>Further explanation</h3>
Given
8.81 g Carbon
91.2 g Chlorine
Molar Mass: 1362.5 g/mol
Required
The empirical formula and molecular formula
Solution
Mol ratio :
C = 8.81 g : 12.011 g/mol =0.733
Cl = 91.2 g : 35,453 g/mol = 2..572
Divide by 0.733
C : Cl = 1 : 3.5 = 2 : 7
The empirical formula : C₂Cl₇
(The empirical formula)n = the molecular formula
(C₂Cl₇)n = 1362.5
(2x12.011+7x35.453)n=1362.5
(272.193)n=1362.5
n = 5
Purple stem plants can be formed by genetics, they use their energy slightly different from other plants, they use less energy, but that may also be because of bad nutrition, and because they may be hungry for nutrients.
