We got the following:
m = 78kg
h = 6m
g = 9.8 m/

≈ 10 m/

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A = ?
As we know A = Ep = mgh -> potential energy
so the answer would be A = 78 * 6 * 10 = 4680 Joule
You can use photo math for This
The 2nd Law of Motion states acceleration is produced when a n unbalanced force acts on an object (mass) The more mass the object has the more net force has to be used to move it.
Examples:
If you use the same force to push a truck and push a car, the car will have more acceleration than the truck, because the car has less mass.
It's easier to push a empty shopping cart then a full one, because the full one has more mass than the empty one. This means more force is required to push the full shopping cart.
Air is a mixture.
as per definition, mixture is a combination we get after adding two or more things together in any proportion.
air is a mixture because it contains a number of gases like nitrogen , oxygen, carbon dioxide. it also contains dust particles, small organisms, water vapors etc.
carbon monoxide is not a mixture as it is formed from fixed proportion of carbon and oxygen.
similarly, water is is not a mixture as it is formed from fixed proportion of hydrogen and oxygen.