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kari74 [83]
3 years ago
13

What type of spectrum is emitted by a low-density luminous cloud of hot gases?

Physics
1 answer:
hoa [83]3 years ago
5 0

The answer is Emission

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a 5.5 g dart is fired into a block of wood with a mass of 22.6 g. the wood block is initially at rest on a 1.5 m tall post. afte
IgorLugansk [536]
<span>From the problem alone we can say that the dart and the block of wood combined into a single object moving together at the end. With that clue we know that the collision is an inelastic collision. The formula of an inelastic collision is:

m_{1}v_{1i}+m_{2}v_{2i}=(m_{1}+m_{2})v_{f}

First let us sort out our given:Mass should be in kg to get the proper answer. Now let's assign m1 as the mass of the dart and m2 as the mass of the block. 
m1 = 5.5g

5.5g x \frac{1kg}{1000g}= 0.0055kg

m2 = 22.6g

22.6g x \frac{1kg}{1000g}= 0.0226kg

So now we settled that we can set our given as:
M1 = .0055 kg
v1i = ?
M2 = 0.0226 kg
v2i = 0 m/s
dx = 2.5 m
dy = -1.5 m

Now you can see that we have 2 unknowns: v1i and vf. We need the vf to solve for the initial velocity of the dart or object 1. We have other given to consider, so we can make use of that to get our missing vf. 

Now, vf is the horizontal velocity after the collision. We do this by first using the equations for projectiles considering that we have an x and y dimension to consider. We use the y dimension to get the x. 
</span>

dy = -1.5 m 

a = 9.8m/s^2

viy = 0 (take note that the initial vertical velocity is 0)

t = ?

<span>We can use the UAM equations to solve for the time in the y-dimension (vertical) to get the horizontal velocity. 

dy = v_{iy}t +  \frac{1}{2} at^{2}</span>

1.5 = (0)t+\frac{1}{2} (9.8)t^{2}

<span>1.5 = \frac{1}{2} (9.8)t^{2}

\frac{(2)(1.5)}{9.8}=t^{2}

\frac{(3)}{9.8}=t^{2}

\sqrt{0.3061} = \sqrt{t^{2}

0.553s = t

Now using this, we can get the horizontal (x-dimension) velocity using the formula:
v_{x} =d_{x}t and our given earlier for the horizontal distance is 2.5m and we solved for time 0.553s. Let's put that into our equation:
v_{x} =d_{x}t
v_{x} =(2.5m)(0.553s) 
v_{x} =4.52m/s

Now we finally have our vf or velocity after the collision. Now let's get back to the equation.

m_{1}v_{1i}+m_{2}v_{2i}=(m_{1}+m_{2})v_{f}

From this we can derive the equation for v1i by isolating it. 

v_{1i}= \frac{((m_{1}+m_{2})v_{f})-(m_{2}v_{2i})}{m_{1}}

Now let's put in all our given and what we solved:

v_{1i}= \frac{((0.0055kg+0.0226kg)4.52m/s)-((0.0226kg)0m/s)}{0.0055kg}

v_{1i}= \frac{(0.0281kg)4.52m/s)}{0.0055kg}

v_{1i}= \frac{0.127012kg.m/s}{0.0055kg}

v_{1i}= 23.09m/s

The initial speed of the dart is 23.09 m/s or 23.10 m/s.</span>
7 0
3 years ago
PLS HELP ASAP!!! <br> I don’t understand this at all
Mnenie [13.5K]

Answer:

The part that completes the nuclear equation is:

           ^{221}_{87}Fr

Explanation:

<h2>A) Preliminar explanation</h2>

The <em>nuclear equation</em> represents a nuclear reaction: the change of the nucleus of an atom.

The given equation represents an actinium atom releasing an alpha particle.

This is the meaning of each part of the equation:

  • Ac is the chemical symbol of actinium
  • The superscript to the left of the chemical symbol is the mass number of the atom (number of protons plus number of neutrons). The mass number is 225.
  • The subscript to the left of the chemical symbol is the atomic number of the atom (number of protons). The atomic number is 89.

  • ^4_2He is the symbol of the alpha particle. It is an atom of helium
  • The mass number is 4
  • The atomic number is 2

<h2>B) Solution</h2>

To <em>complete the nuclear equation </em>you must do two balances: mass number balance and atomic number balance.

<u>i) Mass number balance</u>

  • 225 = A + 4 ⇒ A = 225 - 4 = 221

<u>ii) Atomic number balance</u>

  • 89 = Z + 2 ⇒ Z = 89 - 2 = 87

Therefore, the mass number of the unknown atom is 221, and the atomic number is 87.

From a periodic table, the element with atomic number 87 is francium, Fr.

Now, you have the chemical symbol, the atomic number, and the mass number of the unknown atom, which lets you to write the atom that completes the <em>nuclear equation</em>.

           ^{221}_{87}Fr

7 0
3 years ago
List three (3) specific examples of each biological<br> Homeostasis:<br> Metabolism:<br> Growth:
Andre45 [30]

Answer:

Homeostasis: When bacteria or viruses that can make you ill get into your body, your lymphatic system kicks in to help maintain homeostasis.

Metabolism: The processes of making and breaking down glucose molecules are example of metabolism.(respiration and photosynthesis)

Growth:The liver continues to form new cells to replace senescent and dying ones.

Hope these examples help you.

4 0
3 years ago
The rising and setting of the Moon is mostly caused by *
frez [133]

Answer:

Hey mate......

Explanation:

This is ur answer.....

<h2><em>A. Rotation of Earth</em></h2>

<em>The moon rises in the east and sets in the west, each and every day. It has to. The rising and setting of all celestial objects is due to Earth's continuous daily spin beneath the sky</em><em>.</em>

Hope it helps!

Brainliest pls!

Follow me! :)

4 0
3 years ago
Read 2 more answers
An above ground swimming pool of 30 ft diameter and 5 ft depth is to be filled from a garden hose (smooth interior) of length 10
STALIN [3.7K]

This question involves the concepts of dynamic pressure, volume flow rate, and flow speed.

It will take "5.1 hours" to fill the pool.

First, we will use the formula for the dynamic pressure to find out the flow speed of water:

P=\frac{1}{2}\rho v^2\\\\v=\sqrt{\frac{2P}{\rho}}

where,

v = flow speed = ?

P = Dynamic Pressure = 55 psi(\frac{6894.76\ Pa}{1\ psi}) = 379212 Pa

\rho = density of water = 1000 kg/m³

Therefore,

v=\sqrt{\frac{2(379212\ Pa)}{1000\ kg/m^3}}

v = 27.54 m/s

Now, we will use the formula for volume flow rate of water coming from the hose to find out the time taken by the pool to be filled:

\frac{V}{t} = Av\\\\t =\frac{V}{Av}

where,

t = time to fill the pool = ?

A = Area of the mouth of hose = \frac{\pi (0.015875\ m)^2}{4} = 1.98 x 10⁻⁴ m²

V = Volume of the pool = (Area of pool)(depth of pool) = A(1.524 m)

V = [\frac{\pi (9.144\ m)^2}{4}][1.524\ m] = 100.1 m³

Therefore,

t = \frac{(100.1\ m^3)}{(1.98\ x\ 10^{-4}\ m^2)(27.54\ m/s)}\\\\

<u>t = 18353.5 s = 305.9 min = 5.1 hours</u>

Learn more about dynamic pressure here:

brainly.com/question/13155610?referrer=searchResults

7 0
3 years ago
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