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4 years ago

How many galaxies are present in the observable universe?

Physics

2 answers:

strojnjashka [21]4 years ago

6 0

Answer:

100 billion i think

Explanation:

marissa [1.9K]4 years ago

5 0

There are at least 2 trillion galaxies present in the observable universe.

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Which artist of the northern European Renaissance, shown in this self-portrait, was also a block printer and engraver?

kicyunya [14]

It's very hard to see the self-portrait, so I can't identify him.

6 0

3 years ago

Read 2 more answers

Lightning flashes one mile (1609 m) away from you. How much time does it take the light to travel that distance?

hichkok12 [17]

Answer:

$t=5.36\times 10^{-6}\ s$

Explanation:

Given that,

Lightning flashes one mile (1609 m) away from you.

We need to find the time it take the light to travel that distance. Let the time be t. We know that,

speed = distance/time

$t=\dfrac{d}{v}\\\\t=\dfrac{1609}{3\cdot10^{8}}\\\\=5.36\times 10^{-6}\ s$

So, the required time is $5.36\times 10^{-6}\ s$

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3 years ago

The speed of a car is decreased uniformly from 30. meters per second to 10. meters per second in 4.0 seconds. What was the car's

masha68 [24]

Acceleration (magnitude anyway) = (change in speed) / (time for the change) .

Change in speed = (10 - 30) = -20 m/s

Time for the change = 4.0sec

Magnitude of acceleration = -20/4 = <em>-5 m/s² </em>

3 0

3 years ago

Read 2 more answers

As you may well know, placing metal objects inside a microwave oven can generate sparks. Two of your friends are arguing over th

poizon [28]

Answer:

$4.048\times 10^{-7}\ m$

Explanation:

h = Planck's constant = $6.626\times 10^{-34}\ m^2kg/s$

c = Speed of light = $3\times 10^8\ m/s$

E = Energy = $4.91\times 10^{-19}\ J$

Wavelength ejected is given by

$\lambda=\dfrac{hc}{E}\\\Rightarrow \lambda=\dfrac{6.626\times 10^{-34}\times 3\times 10^8}{4.91\times 10^{-19}}\\\Rightarrow \lambda=4.048\times 10^{-7}\ m$

The maximum wavelength in angstroms of the radiation that will eject electrons from the metal is $4.048\times 10^{-7}\ m$

4 0

3 years ago

Two sound waves, from two different sources with the same frequency of 420 Hz travel in the same direction at 336 m/s. The sourc

Tresset [83]

Answer:

Pi(3.14) radians or 180º degrees

Explanation:

First of all, we need to obtain the wavelength of a wave traveling to the speed of sound and 420 Hz of frequency.

The formula is:

$l=wavevelocity/frequency$

where l = wavelength in meters

With current values:

l = 336 [m/s]/420[1/s] = 0.8 meters

Since a complete cycle (360º or 2pi radians) needs 0.8 meters to complete, 0.4 meters or 40 cm is just half of it, making a 180º degree phase or 3.14 radians.

8 0

3 years ago