Answer:
(a) 
(b) 
Explanation:
(a) Since a constant external force is applied to the body, it is under an uniformly accelerated motion. Using the following kinematic equation, we calculate the final velocity of the mass if it is initially at rest(
):
According to Newton's second law:
Replacing (2) in (1):
(b) In this case we have 
. So, we use the final velocity equation:
Answer:
The pressure of liquid column is given by p=hpg, where h is depth, p is density and g is acceleration due to gravity.
Therefore, pressure of the liquid column increases with depth. The height of the blood column in a human body is more at feet than at the brain. Therefore, the blood pressure in humans is greater at the feet than the brain.
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
The best logical answer is A
