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Mekhanik [1.2K]
2 years ago
5

What is the mass number of a potassium atom that has 20 neutrons

Physics
1 answer:
posledela2 years ago
6 0
 <span>The mass of potassium is 39. This is obtained by adding the 19 protons and 20 neutrons found inside the nucleus</span>


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What forms when two air masses meet and create weather?
Minchanka [31]
When two different air masses meet, a boundary is formed. the boundary between two air masses is called a front. weather at a front is usually cloudy and stormy. there at four different fronts: cold, warm, stationary, and occluded
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3 years ago
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A 0.105- kg hockey puck moving at 24 m/s is caught and held by a 75-kg goalie at rest. With what speed does the goalie slide on
Veseljchak [2.6K]

Answer:

<u><em>0.03 m/s</em></u>

Explanation:

<em>Applying law of conservation of momentum, </em>

  • <em>m₁v₁ + m₂v₂ = (m₁ + m₂)v</em>
  • <em>0.105(24) + 75(0) = (0.105 + 75)v</em>
  • <em>75.105v = 2.52</em>
  • <em>v = 2.52/75.105</em>
  • <em>v = </em><u><em>0.03 m/s</em></u>
3 0
2 years ago
HELP PLS MARKING BRANLIST 100 pts TAKING TEST RN
AlladinOne [14]

Answer:

15 m/s^2 The first thing to calculate is the difference between the final and initial velocities. So 180 m/s - 120 m/s = 60 m/s So the plane changed velocity by a total of 60 m/s. Now divide that change in velocity by the amount of time taken to cause that change in velocity, giving 60 m/s / 4.0 s = 15.0 m/s^2 Since you only have 2 significaant figures, round the result to 2 significant figures giving 15 m/s^2

Explanation:

8 0
3 years ago
Compare and contrast electric potential energy and electric potential difference? Explain.
forsale [732]

Answer:

<u><em>Electric Potential Energy:</em></u>

The energy that is needed to move a charge against an electric firld is called Electric Potential Energy

<u><em>Electric Potential Difference:</em></u>

The amount of work done in carrying a unit charge from one point to an other in an electric field is called Electric Potential Difference.

<u><em>Relation:</em></u>

Relation between Electric potential and electrical potential energy is given by

\delta V=\frac{PE}{q}

Here PE represents Electric potential energy

and \delta V is Electric potential difference

it means electric potential difference is the difference in electric potential energy divided by the charge.

6 0
2 years ago
One end of an insulated metal rod is maintained at 100 ∘C and the other end is maintained at 0.00 ∘C by an ice–water mixture. Th
lozanna [386]

Answer:

k=105.0359\times 10^4\,W.m^{-1}.K^{-1}

Explanation:

Given:

temperature at the hotter end, T_H=100^{\circ}C

temperature at the cooler end, T_C=0^{\circ}C

length of rod through which the heat travels, dx=0.7\,m

cross-sectional area of rod, A=1.1\times 10^{-4}\,cm^2

mass of ice melted at zero degree Celsius, m=8.7\times 10^{-3}\,kg

time taken for the melting of ice, t=15\times60=900\,s

thermal conductivity k=?

By Fourier's Law of conduction we have:

\dot{Q}=k.A.\frac{dT}{dx}......................................(1)

where:

\dot{Q}=rate of heat transfer

dT= temperature difference across the length dx

Now, we need the total heat transfer according to the condition:

we know the latent heat of fusion of ice,  L = 334000\,J.kg^{-1}

Q=m.L

Q=8.7\times 10^{-3}\times 334000

Q=2905.8\,J

Now the heat rate:

\dot{Q}=\frac{Q}{t}

\dot{Q}=\frac{2905.8}{900}

\dot{Q}=3.2287\,W

Now using eq,(1)

3.2287=k\times 1.1\times 10^{-4} \times \frac{100}{0.7}

k=205.4606\,W.m^{-1}.K^{-1}

8 0
3 years ago
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