Answer:
D. 4Al + 3O2 → 2Al2O3
Explanation:
Chemical reactions involves the chemical combination of two or more substances called REACTANTS to yield other substances called PRODUCTS. However, in accordance with the LAW OF CONSERVATION OF MASS, the amount of reactants must be equal to that of the products.
To accomplish this, the reaction must be BALANCED. A balanced equation is an equation in which the number of atoms of each element in the reactant side equals the number of atoms in the product side. In this reaction involving Aluminum and Oxygen to give Aluminum oxide as follows:
Al + 02 → Al2O3
A coefficient is used to balance the number of atoms on both sides of the equation as follows:
4Al + 3O2 → 2Al2O3
Answer:
The ball fell 275.625 meters after 7.5 seconds
Explanation:
<u>Free fall
</u>
If an object is left on free air (no friction), it describes an accelerated motion in the vertical direction, powered exclusively by the acceleration of gravity. The formulas needed to compute the different magnitudes involved are
Where 
is the final speed of the object in free fall, assumed positive downwards, t is the time elapsed since the release and y is the vertical distance traveled by the object
The ball was dropped from a cliff. We need to calculate the vertical distance the ball went down in t=7.5 seconds. We'll use the formula
Answer:
when we lower a bucket into a well to fetch water, the work done by gravity is positive since force and displacement are in the same direction.
Explanation:
