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.
Mole fraction<span> is another way of expressing the concentration of a solution or mixture. It is equal to the </span>moles<span> of one component divided by the total </span><span>moles.
mass CH4O = 0.270 (51) = 13.77 g methanol
water = 51 - 13.77 = 37.23 g water
Hope this answers the question. Have a nice day.</span>
Answer:
The main difference between the two models is <em>the position of the electron in the atom</em>.
Explanation:
- <em>Bohr model:</em> The electrons are moved around the nucleus in circular definite paths (orbitals or shells). Also, he could not find or detect the exact position of electron.
- <em>Electron cloud model:</em> It is supposed by Erwin Schrodinger. He showed that the emission spectra of the atom is the way to detect the probability of electron position.
Answer: The moon
Explanation: hope this helps.