Answer:
1. Two materials that can be scratched by an iron nail are <u>zinc</u> and <u>aluminum</u>
2. A substance that can be scratched by an iron nail but not a penny is;
Nickel
Explanation:
The hardness of a material can be defined as its ability to resist being plastically deformed at a location due to mechanical scratching, abrasion or indentation
The Mohs hardness scale provides a ranking of materials in the order of hardness with a material having a higher Mohs hardness number being able to scratch other materials which have a lower Mohs hardness number
1. From the Mohs scale of hardness, iron which has an harness number of 4.5 can scratch zinc which has an harness number of 2.5, and iron can also scratch aluminum which has an hardness number of 2.5 to 3
2. A penny is made from copper plated material and will have an outer layer hardness of copper which has an hardness number of 3 on the Mohs scale
Therefore, a penny cannot scratch a material mode of nickel which has an hardness number of 4, while iron which has an hardness of 4.5 will scratch a nickel material
<span>We know that pressure is the force applied into a surface, in our case the wall of the room, so then first we will calculate the surface of this wall:
S = 2.2 * 3.2 = 7.04 m2
Then we also know the atmospheric pressure in normal conditions is 1 atm. That is the same 1 atm = 101325 Pascals or 101325 N/m2
Now we need to use the formula : P = F/S where P is pressure, F is force and S is surface to calculate the force:
F = P * S = 101325 * 7.04 = 713,328 Newtons
Conclusion: the force acts on the wall due the air inside the room is 713,328 N</span>
Answer:
D
Explanation:
appearance is not a imp factor . location could be imp. becoz a proper environment is need to study such courses.
The electric force between two charges is:
F = (9 x 10⁹) Q₁ Q₂ / D²
F is the force, in Newtons
Q₁ and Q₂ are the two charges, in Coulombs
D is the distance between them, in meters
For these two particles:
F = (9 x 10⁹) (0.35) (0.35) / (1)²
F = (9 x 0.35 x 0.35 x 10⁹) / (1)
<em>F = 1.10 x 10⁹ Newtons</em>
Thatsa lotta force . . . like <em>124 thousand tons</em> !
The reason it's so big is because the charges in this question are so big ... 0.35 Coulombs each. 1 Coulomb is a huge amount of charge.
Each of the particles feels the same force, pushing it away from the other particle. (The electric force between two charges is always the same in both directions, just like the gravitational force between two masses.)