Answer:

Explanation:
initially the merry go round is at rest
after 6.73 s the merry go round will accelerates to 20 rpm
so final angular speed is given as



so final tangential speed is given as


now average acceleration of the girl is given as



Answer: 134 neutrons are there in the nucleus of Radon-220
Explanation:
Atomic number : It is defined as the number of electrons or number of protons present in a neutral atom.
Thus, number of protons = atomic number = 86
Mass number is the number of the entities present in the nucleus which is the equal to the sum of the number of protons and electrons.
Mass number = Number of protons + Number of neutrons
220 = 86 + Number of neutrons
Number of neutrons = 134
Answer:
Option b. Effective nuclear charge increases as we move to the right across a row in the periodic table
Explanation:
The <em>effective nuclear charge </em>is a measure of how strong the protons in the nucleus of an atom attract the outermost electrons of such atom.
The <em>effective nuclear charge</em> is the net positive charge experienced by valence electrons and is calculated (as an approximation) by the equation: Zeff = Z – S, where Z is the atomic number and S is the number of shielding electrons.
The shielding electrons are those electrons in between the interesting electrons and the nucleus of the atom.
Since the shielding electrons are closer to the nucleus, they repel the outermost electrons and so cancel some of the attraction exerted by the positive charge of the nucleus, meaning that the outermost electrons feel less the efect of attraction of the protons. That is why in the equation of Zeff, the shielding electrons (S) subtract the total from the atomic number Z.
The <em>effective nuclear charge</em>, then, is responsible for some properties and trends in the periodic table. Here, you can see how this explains the trend of the atomic radius (size of the atom) accross a row in the periodic table.
- As the<em> effective nuclear charge</em> is larger, in a same row of the periodic table, the shielding effect is lower, the outermost electrons are more strongly attracted by the nucleus, and the size of the atoms decrease. That is why as we move to the right in the periodic table, the size of the atoms decrease.
Answer:
9.8m/s
Explanation:
acceleration due to gravity is independent of mass
Answer:
The number of turns, N = 1750
Explanation:
It is given that,
The inner radius of a toroid, r = 12 cm
Outer radius, r' = 15 cm
The magnetic field at points within the coils 14 cm from its center is, 
R = 14 cm = 0.14 m
Current, I = 1.5 A
The formula for the magnetic field at some distance from its center is given by :



N = 1750
So, the number of turns must have in a toroidal solenoid is 1750. Hence, this is the required solution.