The appearance of spiral galaxies vary in the following ways:
A. They vary in how tightly their arms are wound.
D. Some have a band of stars and materials through their middle, but others do not
Spiral galaxies are the galaxies where the gas clouds and the stars are concentrated in spiral arms.
Examples of spiral galaxies include<em> Milky way, Sunflower Galaxy, Andromeda Galaxy, </em>etc.
It should be noted that <em>spiral galaxies</em> vary in how tightly their arms are wound while some have a band of stars and materials through their middle, but others do not.
Read related link on:
brainly.com/question/20785889
Electromagnetic waves do not require material medium for propagation. Radiowaves have the longest wavelength but the least frequency.
Gamma ray has the shortest wavelength but the highest frequency.
The gamma rays and x-rays due to their high frequency, they can disturb the medium they pass through. They have high energy that can cause damage to the matter the come across.
Angular velocity is the rate of change of angle of a body, i.e. omega = v / r = (2*pi*r)/ r*t = (2*pi)/ T. where T is the time period of whatever is rotating and r is the radius of the circle. So if a circular disc is spinning at 1 m/s then the angular velocity of it is 2*pi radians/ second.
Answer:
a) μ = 0.602 and b) μ = 0.475
Explanation:
a) Let's use Newton's second law for this exercise. The reference system the x axis is parallel to the floor and the axis and perpendicular.
Y Axis
N-W = 0
N = W
X axis
F-fr = ma
The friction force equation is
fr = μN
At the point where the movement begins the acceleration is zero
Let's replace
F = μ (mg) = 0
F = μ mg
μ = F / mg
μ = 171/29 9.8
μ = 0.602
b) in this case we have the same formula, but the friction is kinetic
μ = F2 / mg
μ = 135/29 9.8
μ = 0.475
The apparent weight of the child is 437.5 N.
<h3>Calculation:</h3>
The weight of a person/object moving up with an acceleration "a" is given by
W = m (g + a)
where,
W = apparent weight
m = mass of the person/object
g = acceleration due to gravity = 10 m/s²
a = acceleration of the object/person
Given,
m = 35 kg
a = 2.5 m/s²
To find,
W =?
Put the value sin the formula,
W = m (g + a)
W = 35 (10 + 2.5)
= 35 (12.5)
= 437.5 N
Therefore, the apparent weight of the child is 437.5 N.
Learn more about apparent weight here:
brainly.com/question/13554234
#SPJ4
