Answer: In summary, work is done when a force acts upon an object to cause a displacement. Three quantities must be known in order to calculate the amount of work. Those three quantities are force, displacement and the angle between the force and the displacement.
Explanation:
In the Periodic Table, elements with similar reactivity and similar properties are found under the same column.
In fact, elements in the same columns are said to be in the same "group", and they have the same number of valence electrons, i.e. the same number of electrons in the outermost shell. This is the main characteristics that determine how an element reacts with other elements.
For instance, Litium (Li), sodium (Na) and potassium (K) are all in the first group, and they both have 1 valence electrons. This means they can easily give away this electron to an atom of another element forming bonds with it, and therefore they have high reactivity. Instead, elements of the 8th group are called "noble gases", and they all have similar properties: they all have the outermost shell full of eletrons, so they have zero valence electrons and so they have little or no reactivity at all. Example of elements in this group are Neon (Ne) and Argon (Ar).
Answer:
D = 104.4 m
Explanation:
We are given two displacement vectors. One in north direction other in east direction. We know that north and east directions are perpendicular to each other. Hence, the displacements vectors are also perpendicular to each other. Therefore, there resultant can be found by using Pythagora's Theorem like rectangular components method.
D = √(Dₓ² + Dy²)
where,
D = Magnitude of vector sum of both displacements = ?
Dₓ = Magnitude of Displacement Vector in east direction = 30 m
Dy = Magnitude of Displacement Vector in North Direction = 100 m
Therefore,
D = √[(30 m)² + (100 m)²]
<u>D = 104.4 m</u>
14. Answer;
-There are two potassium ions for each ion of sulfur.
Explanation;
The formula K2S indicates that there are two potassium ions for each ion of sulfur.
-K2S is the formula of potassium sulfide.
- From the formula; two potassium atoms combines with 1 atom of sulfur to form the compound. In other words the ratio of potassium and sulfur atoms in the compound is 2 : 1.
15. Answer;
-Lithium fluoride
Explanation;
-Fluorine, F, forms a binary ionic compound with lithium, Li. The name of the compound is lithium fluoride.
- A compound is a substance that is formed when two or more atoms from different elements are chemically bonded. For example Lithium fluoride is a compound that is made of fluorine atom and lithium atom that are chemically combined.
16. Answer;
-Carbon-12 atom
Explanation;
The standard on which the atomic mass unit is based is the mass of a carbon-12 atom.
-Atomic mass is the quantity of matter contained in an atom of an element. -The atomic mass is expressed as a multiple of one-twelfth the mass of the carbon-12 atom, which is assigned an atomic mass of 12 units.
17. Answer;
- Non-metal fluorine
Explanation;
-Two highly reactive elements in Period 2 are the metal lithium and the non-metal fluorine.
-Elements in period 2 often have the most extreme properties in their respective groups. Fluorine is the most reactive halogen, neon is the most inert noble gas, and lithium is the least reactive alkali metal, but the most reactive metal in group 2.
Answer:
the direction of acceleration of the vehicle is the same direction of its velocity of car
s acceleration has the opposite direction to the car speed.
Explanation:
The initial acceleration of the car can be calculated with
v = v₀ + a t
a = (v-v₀) t
indicate that the initial velocity is zero (v₀ = 0 m / s)
a = v / t
a = 300 / t
the direction of acceleration of the vehicle is the same direction of its acceleration movement.
When the car collides with the wall, it exerts a force in the opposite direction that stops the vehicle, therefore this acceleration has the opposite direction to the car speed. But your module must be much larger since the distance traveled to stop is small