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Ipatiy [6.2K]
3 years ago
14

Which of the following is not a way that astronomers can find how much dark matter there is in cluster of galaxies?

Physics
1 answer:
Tpy6a [65]3 years ago
6 0

Answer:

<em>b. Observe the radio waves coming from all dark matter; from the strength of the radio waves from each cluster, estimate the amount of dark matter needed to produce them.</em>

<em></em>

Explanation:

The universe is thought to be made up of 85% dark matters. <em>Dark matter is called dark because it does not appear to interact with the electromagnetic field, which means it doesn't absorb, reflect or emit electromagnetic radiation, and is therefore difficult to detect. This means that option b is wrong since radio wave is an electromagnetic wave</em>. Dark matter is a form of matter that makes up  about a quarter of the total mass–energy density of the universe. Dark matter was theorized due a variety of astrophysical observations and gravitational effects that cannot be explained by accepted theories of gravity unless there were more matter in the universe than can be seen.

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1. An asphalt block has a mass of 90 kg and a volume of 0.075 m. Determines the density of the asphalt.
Kisachek [45]

Answer:

1. Density = 1200[kg/m^3]; 2. Volume= 0.005775[m^3], mass= 15.59[kg]

Explanation:

1. We know that the density is defined by the following expression.

Density = \frac{mass}{volume} \\where:\\mass=90[kg]\\volume=0.075[m^{3} ]\\density=\frac{90}{0.075} \\density=1200[\frac{kg}{m^{3} }]

2. First we need to convert the units to meters.

wide = 35[cm] = 35/100 = 0.35[m]

long = 11 [dm] =  11 decimeters = 11/10 = 1.1[m]

Thick = 15[mm] = 15/1000 = 0.015[m]

Now we can find the density using the expression for the density.

density= \frac{mass}{volume} \\where:\\volume = wide*long*thick\\volume=0.35*1.1*0.015 = 0.005775[m^3]\\\\mass= density*volume = 2700*0.005775 = 15.59[kg]

7 0
3 years ago
A box has a mass of 400 g. What minimum force is needed to lift it?
mart [117]

Answer: 3.92 N.

Explanation:

Your box weighs 400g, or 0.4kg. In order to lift it, you need to overcome the force of gravity. F = ma, and acceleration due to gravity is -9.8 m/s^2. So gravity acts on the box with a force of 0.4 kg * -9.8 m/s^2 = -3.92 N. A force of +3.92 N is required to overcome this.

5 0
3 years ago
12
tensa zangetsu [6.8K]

Answer:

1) Determine the domain of the following functions: d ... 3) If g(x) = x + 3 and f(x)= x² – 2x, find the value of f(g(a)). ... 6) Given the graph of f(x) to the right, determine: ... 8) Given f(x)= x? and g(x)= 2* The inverse of g is a function, but the inverse off is ... -3(x-1)= -5 4 (-3). -3x+ 3 = y. 10) The graph of a function f (x) is given at the.

Explanation:

3 0
3 years ago
an open tank has the shape of a right circular cone (see figure). the tank is 8 feet across the top and 6 feet high. how much wo
Liono4ka [1.6K]

The amount of work done in emptying the tank by pumping the water over the top edge is 163.01* 10³ ft-lbs.

Given that, the tank is 8 feet across the top and 6 feet high

By the property of similar triangles, 4/6 = r/y

6r = 4y

r = 4/6*y = 2/3*y

Each disc is a circle with area, A = π(2/3*y)² = 4π/9*y²

The weight of each disc is m = ρw* A

m = 62.4* 4π/9*y² = 87.08*y²

The distance pumped is 6-y.

The work done in pumping the tank by pumping the water over the top edge is

W = 87.08 ∫(6-y)y² dy

W = 87.08 ∫(6y³ - y²) dy

W =  87.08 [6y⁴/4 - y³/3]

W =  87.08 [3y⁴/2- y³/3]

The limits are from 0 to 6.

W =  87.08 [3*6⁴/2 - 6³/3] = 87.08* [9*6³ - 2*36] = 87.08(1872) = 163013.76 ft-lbs

The amount of work done in emptying the tank by pumping the water over the top edge is 163013.76 ft-lbs.

To know more about work done:

brainly.com/question/16650139

#SPJ4

7 0
1 year ago
A bungee jumper of mass m = 65 kg jumps from a bridge.
yawa3891 [41]

To solve the problem it is necessary to apply energy conservation.

By definition we know that kinetic energy is equal to potential energy, therefore

PE = KE

mgh = \frac{1}{2}mv^2

Where,

m = mass

g = gravitaty constat

v = velocity

h = height

Re-arrange to find h,

h=\frac{v^2}{2g}

Replacing with our values

h=\frac{26^2}{2*9.8}

h = 34.498\approx 34.5m

Therefore the correct answer is C.

3 0
2 years ago
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