What does the big 2 in 2CO2 mean?

Its a coefficient

Explanation:

It has double a normal CO2 has

A number that comes before a compound or molecule e.g 2 in this case is indicating that there are 2 carbon dioxide molecules. Therefore 2CO2 contains: 2×1=2 Carbon atoms.There are four oxygen atoms in the formula 2CO2. The number 2 that is sub-scripted with O determines the number of oxygen atoms, while the number 2 is showing the carbon dioxide atom means how many carbon dioxide is present.

for step 7 table c on the lab "newtons law of action"   the average time it took the car to travel .25 meters   was 1.92 seconds.

the average time it took the car to travel 0.50 meters was 2.61 seconds

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