Answer:
Density of 127 I = 
Also, 
Explanation:
Given, the radius of a nucleus is given as
.
where,
- A is the mass number of the nucleus.
The density of the nucleus is defined as the mass of the nucleus M per unit volume V.

For the nucleus 127 I,
Mass, M = 
Mass number, A = 127.
Therefore, the density of the 127 I nucleus is given by

On comparing with the density of the solid iodine,

J.J. Thomson discovered electrons and noticed that an atom can be divided. Also, he concluded atoms are made of positive cores and negatively charged particles within it.
Reflection: a change in direction of a wave at a boundary between two different media.
sentence: i saw my reflection in the mirror.
refraction: the bending of light as it passes from one transparent substance into another.
sentence: when light goes through glass, it’s a refraction.
diffraction: the bending of waves around the corners of an obstacle.
sentence: spaced tracks on a CD act as a diffraction.
absorption: the process or action by which one thing absorbs or is absorbed by another.
sentence: heat waves hitting the beach usually give most of their energy to the sand.
interference: when two waves lay on each other and their energies are either added together or cancelled out.
sentence: interference waves can be observed with all types of waves.
standing wave: two waves moving in opposite directions. they both have the same amplitude or frequency.
sentence: plucking the string of a guitar is an example of standing waves.
resonance: increased amplitude that occurs when the frequency of a force is equal or close to a natural frequency.
sentence:a buzz in your car that only occurs at a certain speed is an example or resonance.
A child slides down a hill on a toboggan with acceleration of 1.8 m/s2. if she starts from rest, how far has she traveled in: 2 seconds
Answer:
2.4 m
Explanation:
From the question above,
Applying equation of motion,
s = ut+at²/2....................... Equation 1
Where t = time, u = initial velocity, a = acceleration, s = distance.
make s the subject of the equation,
Given: a = 1.8 m/s², t = 2 seconds, u = 0 m/s (from rest)
Substitute these value into equation 1
s = 0(2)+1.8(2²)/2
s = 1.2(4)/2
s = 2.4 m.
Hence she has traveled 2.4 m