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SpyIntel [72]
3 years ago
7

The half-life of a certain element is 100 days. How many half-lives will it be before only one-eighth of this element remains?

Physics
1 answer:
Natalka [10]3 years ago
7 0

Answer:

3

Explanation:

The half-life is the time it takes for the amount of radioactive isotope to halve. Therefore, we have:

- After 1 half-life, only 1/2 of the element will be left

- After 2 half-lives, only 1/4 of the element will be left

- After 3 half-lives, only 1/8 of the element will be left

So, it will take 3 half-lives for the element to become 1/8 of its original amount.

Mathematically, this can be also verified by using the equation

\frac{N(t)}{N_0}=(\frac{1}{2})^\frac{t}{\tau_{1/2}}

where

N(t) is the amount of the element left at time t

N0 is the initial amount of the element

\tau_{1/2} is the half-life

Substituting t=3\tau_{1/2} (3 half-lives), we find

\frac{N(t)}{N_0}=(\frac{1}{2})^3=\frac{1}{8}

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Answer:

Remains the same

Explanation:

The speed of waves of higher and lower frequency both will be same.

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we know that

υ×λ = constant = velocity

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7 0
3 years ago
What is latent heat of fusion?
Naddik [55]

If you have a lump of solid at its melting point ... like ice at 32°F ...
you have to put a certain amount of heat into it just to change it
to water at 32°F.  That amount of heat, that's used just to change
a solid lump into liquid without changing its temperature, is called
the heat of fusion for that substance.

The number is different for every substance.

For water, it takes 336 joules of heat to melt 1 gram of ice
into 1 gram of water, all at 32°F (0°C).
That's an enormous latent heat of fusion ... more than almost any
other known substance.  That's why ice is such a good choice
when you need something to put in your drink to cool it down.
Ice absorbs a huge amount of heat before it melts and the drink
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5 0
3 years ago
Read 2 more answers
A 2:2 kg toy train is con ned to roll along a straight, frictionless track parallel to the x-axis. The train starts at the origi
Liula [17]

Answer:

a) 10.51 J

b) 3.48 m/s

Explanation:

Given data :

mass of train ( M ) = 2.2 kg

Given initial velocity ( u ) = 1.6 m/s

<u>a) calculating work done by the force over the journey of the train</u>

F = mx + b  ------ ( 1 )

m = slope  = ( Δ f / Δ x ) = 2.8 / -7.5 = - 0.373 N/m

x = distance travelled on the x axis by the train = 7.5 m

F = force experienced by the train = 2.8 N

x = 0

∴ b = 2.8

hence equation 1 can be written as

F = ( -0.373) x + 2.8   ----- ( 2 )

hence to determine the work done by the force

W   = \int\limits^7_0 { ( -0.373) x + 2.8  )} \, dx     Note:  the limits are actually 7.5 and 0

∴ W ( work done ) = -10.49 + 21 = 10.51 J

<u>b) calculate the speed of the train at the end of its journey</u>

we will apply the work energy theorem

W = 1/2 m*v^2  -  1/2 m*u^2

∴ V^2 = 2 / M ( W + 1/2 M*u^2 )  ( input values into equation )

 V^2 = 12.11

hence V = 3.48 m/s

6 0
3 years ago
When do we land on Mars ?
lorasvet [3.4K]

Answer:

I think like 2024 or 25

Explanation:

Elon musk will probably go

5 0
3 years ago
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In a given chemical reaction, the energy of the products is greater than the energy of the reactants. Which statement is true fo
Flura [38]

Energy is released in the reaction

Explanation:

In a given where the energy of the products is greater than that of the reactants, we can infer that energy is released in the reaction.

This indicates that the reaction is an exothermic or exergonic reaction.

These reaction types are accompanied by release of energy.

  • In an exothermic change energy is released to the surroundings.
  • The surrounding becomes hotter at the end of the change.
  • This applies in exergonic reaction which leaves a reaction having more energy than it originally started with.

Learn more:

Exothermic process brainly.com/question/10567109

#learnwithBrainly

3 0
3 years ago
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