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 number of moles for co2=mass(g)/molar mass
n=.22/44=.005 mole of CO2
from the equation we see the relationship between the moles of co2 and O2 and we find that they have the same number of moles
So we need .005mole of O2
Multiple the number of moles with avogadro’s number to know the number of O2molecules
.005x6.022 x10^23
Answer:
The atomic number represents the number of protons
Explanation:
They dim unless more volts are added (batteries")
Reptiles arose during the Carboniferous period. Therefore making the answer Reptiles
