Answer:
4.2 x 10⁷N
Explanation:
Given parameters:
Charge on ball:
q₁ = 3C
q₂ = 14C
Distance between balls = 9000m
Unknown:
Force acting on the two balls
Solution:
The force experienced by the two charges is given by coulombs law. It is mathematically expressed as;
F = 
where k = 9 x 10⁹Nm²/C²
q is the charges
r is the distance
Input the variables and solve;
F = 
= 4.2 x 10⁷N
The answers are as follows:
1. B.
A typical atom is made up of three different particles, which are electron, proton and neutron. The proton and the neutron are located inside the nucleus of the atom while the electron orbit round the nucleus.
2. C
The number of proton in an atom determines the atomic number of that atom. Atom are positively charged particles and they do no participate in chemical reactions. The number of proton of an element remain constant at all time while the number of neutrons and the electrons in the atom may change.
3. B.
The first periodic table was created by Dmitri. He arranged the periodic table in such a way that, elements with similar properties fall into the same column in his periodic table. This was because, he arranged the periodic table on the basis of their physical and chemical properties.
4. A
The elements in the periodic table are arranged in horizontal row and vertical column. The column on the periodic table divides the elements into groups.
A row of element on the periodic table is called PERIOD. For elements on the same period, they have the same number of atomic orbitals.
5. A
Chemical symbol refers to the one or two letters which are used to represent a particular element. Chemical symbols are derived in a variety of ways. The chemical symbols make it possible for one to recognize an element quickly and to write it in an abbreviated form when writing chemical equations.
6. A.
An object is said to be ductile if it can be pulled into a long wire. It refers to an element's capacity to be pulled into a thin wire without the element been deformed. This is one of the properties of metals. Ductability makes it easier for one to work with a metal.
7. C
When metals atoms react with other atoms, the metal atoms lose electrons, this is because, metals usually have a low number of electrons in their outermost shells, which they always preferred to donate in order to achieve octet form.
8. B
Particle accelerator is a machine that accelerate elementary particles to very high energies, thus producing beam of charged particles which can be used for a lot of different purposes.
Answer:
Option B. 8.1
Explanation:
From the question given above, the following data were obtained:
Angle θ = 71°
Hypothenus = 25
Adjacent = x
Thus, we can obtain the x component of the vector by using the cosine ratio as illustrated below:
Cos θ = Adjacent /Hypothenus
Cos 71 = x/25
Cross multiply
x = 25 × Cos 71
x = 25 × 0.3256
x = 8.1
Therefore, the x component of the vector is 8.1
Answer:
3m
Explanation:
89.1 MHz means
89.1×10^6 cycles/second.
Electromagnetic radiation (including radio waves) travel at
3.0×10^8meters/second
Wavelength = Speed/Frequency
The wavelength of a
89.1MHz radio signal is
3.0×10^8/89.1x10^6
= 0.03x10^2
= 3meters
Answer:
1. B
2. B
Explanation:
1. he was the only teacher at that time that figured out that everything doesn't revolve around us. he figured it out by a telscope he made from three lens and a tube. its actually pretty cool. He found out that venus first was in front of us.
2. if the earth wasn't at a tilt, then we wouldn't have sessons, when the earth rotate around the sun, the earth is roataing at a title axis. and that changes our seesons, because if we are in south america, and we are in winter time, and south america is cold, then it means that the continent is not getting as much heat from the sun. Does that makes since, because it doesn't sound like it?
