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3 years ago

What evidence is there that the universe is expanding?

2 answers:

7 0

The main evidence is the redshift of galaxies. This means the other galaxies are moving away from us. The Andromeda galaxy is having a blueshift though, meaning it's coming closer. Another piece of evidence is warmth in space.
Hope this helps.

aksik [14]3 years ago

6 0

Answer:

Galaxies moving apart from each other.

Explanation:

It has been observed that the galaxies are moving away from each other. This expansion is an outcome of the Big Bang theory of Universe formation. The observational proof of this is the Redshift observed in the spectrum of faraway galaxies which means that they are moving away. Also, as per Hubble Law, the galaxies which are farther away from us are moving faster as compared to the ones which are closer.

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A nickel (5 cent coin) has a mass of 5.0 g. How many nickels are there in a stack of nickels with a mass of 10.0 kg?

Marrrta [24]

Answer:

2000 nickels

Explanation:

One way to solve proportionality problems, direct and inverse: the simple 3 rule.

If the relationship between the magnitudes is direct (when one magnitude increases so does the other), the simple direct rule of three must be applied.

On the contrary, if the relationship between the magnitudes is inverse (when one magnitude increases the other decreases) the rule of three simple inverse applies.

The simple 3 rule is an operation that helps us quickly solve proportionality problems, both direct and inverse.

To make a simple rule of three we need 3 data: two magnitudes proportional to each other, and a third magnitude. From these, we will find out the fourth term of proportionality.

In the simple three rule, therefore, the proportionality relationship between two known values A and B is established, and knowing a third value C, a fourth value D is calculated.

A -> B

C -> D

Calculation

1 nickel --> 5 g

X? nickel --> 10000g

X = (10000 g * 1 nickel) / 5 g

X = 2000 nickels

7 0

3 years ago

Pot holder should have high insulation and low _____.

kipiarov [429]

Potholder should have high insulation and low conductivity, therefore the correct answer is the option B

<h3>What is insulation?</h3>

Insulation is a type of material used to create barriers to the transmission of the form of energy which either is in form of heat or electricity.

For outdoor trips in cold weather, several thin layers act as better insulating barriers for heat transfer.

The ability of an electric charge or heat to pass through a material is measured by its conductivity. A material is considered a conductor if it offers very little resistance to the flow of thermal or electric energy.

Thus, Potholders should be highly insulated and have low conductivity, therefore the correct answer is the option B

Learn more about insulation from here

brainly.com/question/14363642

#SPJ1

your question seems incomplete, the complete question is

To be effective, a pot holder should have low _____. viscosity conductivity malleability density

3 0

1 year ago

The conducting path between the right hand and the left hand can be modeled as a 9.0-cm-diameter, 140-cm-long cylinder. The aver

Crank

Answer:

The potential difference is 121.069 V

Solution:

As per the question:

Diameter of the cylinder, d = 9.0 cm = 0.09 m

Length of the cylinder, l = 40 cm = 1.4 m

Average Resistivity, $\rho = 5.5\ \Omega-m$

Current, I = 100 mA = 0.1 A

Now,

To calculate the potential difference between the hands:

Cross- sectional Area of the Cylinder, A = $\pi (\frac{d}{2})^{2} = 6.36\times 10^{- 3}\ m^{2}$

Resistivity is given by:

$\rho = R\frac{A}{l}$

$R = \rho \frac{l}{A}$

$R = 5.5\times \frac{1.4}{6.36\times 10^{- 3}} = 1210.69\ \Omega$

Now, using Ohm's Law:

V = IR

$V = 0.1\times 1210.69 = 121.069\ V$

4 0

4 years ago

A DJ starts up her phonograph player. The turntable accelerates uniformly from rest, and takes t1 = 11.9 seconds to get up to it

Degger [83]

Answer:

a) $\omega_1=8.168\,rad.s^{-1}$

b) $n_1=7.735 \,rev$

c) $\alpha_1 =0.6864\,rad.s^{-2}$

d) $\alpha_2=4.1454\,rad.s^{-2}$

e) $t_2=1.061\,s$

Explanation:

Given that:

initial speed of turntable, $N_0=0\,rpm\Rightarrow \omega_0=0\,rad.s^{-1}$

full speed of rotation, $N_1=78 \,rpm\Rightarrow \omega_1=\frac{78\times 2\pi}{60}=8.168\,rad.s^{-1}$

time taken to reach full speed from rest, $t_1=11.9\,s$

final speed after the change, $N_2=120\,rpm\Rightarrow \omega_2=\frac{120\times 2\pi}{60}=12.5664\,rad.s^{-1}$

no. of revolutions made to reach the new final speed, $n_2=11\,rev$

(a)

∵ 1 rev = 2π radians

∴ angular speed ω:

$\omega=\frac{2\pi.N}{60}\, rad.s^{-1}$

where N = angular speed in rpm.

putting the respective values from case 1 we've

$\omega_1=\frac{2\pi\times 78}{60}\, rad.s^{-1}$

$\omega_1=8.168\,rad.s^{-1}$

(c)

using the equation of motion:

$\omega_1=\omega_0+\alpha . t_1$

here α is the angular acceleration

$78=0+\alpha_1\times 11.9$

$\alpha_1 = \frac{8.168 }{11.9}$

$\alpha_1 =0.6864\,rad.s^{-2}$

(b)

using the equation of motion:

$\omega_1\,^2=\omega_0\,^2+2.\alpha_1 .n_1$

$8.168^2=0^2+2\times 0.6864\times n_1$

$n_1=48.6003\,rad$

$n_1=\frac{48.6003}{2\pi}$

$n_1=7.735\, rev$

(d)

using equation of motion:

$\omega_2\,^2=\omega_1\,^2+2.\alpha_2 .n_2$

$12.5664^2=8.168^2+2\alpha_2\times 11$

$\alpha_2=4.1454\,rad.s^{-2}$

(e)

using the equation of motion:

$\omega_2=\omega_1+\alpha_2 . t_2$

$12.5664=8.168+4.1454\times t_2$

$t_2=1.061\,s$

4 0

4 years ago

A kangaroo can jump straight up to a height of 2.0 m. What is its takeoff speed

12345 [234]

7.17m/s glad I could help

5 0

3 years ago