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madam [21]
3 years ago
6

Please help me I need these extra credit points plz plz plz

Physics
2 answers:
KengaRu [80]3 years ago
6 0

Answer:

2 half lives have passed, the rock layer is 4,000 years old

Explanation:

It takes 2,000 years for half of the 400 atoms to decay which leaves you with 200 atoms. It then takes another 2,000 years for half of the 200 atoms to decay with leaves you with 100 atoms after a total of 4,000 years and 2 half lives.

VashaNatasha [74]3 years ago
5 0
Two half lives so it is 4000 years old
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A person in bare feet is standing under a tree during a thunderstorm, seeking shelter from the rain. A lightning strike hits the
Anni [7]

Answer:

I=38.181\ A is the current through the body of the man.

E=34.5\ J energy dissipated.

Explanation:

Given:

  • time for which the current lasted, t=43\times 10^{-6}\ s
  • potential difference between the feet, V=21000\ V
  • resistance between the feet, R=550\ \Omega

<u>Now, from the Ohm's law we have:</u>

I=\frac{V}{R}

I=\frac{21000}{550}

I=38.181\ A is the current through the body of the man.

<u>Energy dissipated in the body:</u>

E=I^2.R.t

E=38.181^2\times 550\times 43\times 10^{-6}

E=34.5\ J

5 0
3 years ago
245289457u2895785/+55891235723895718957=
Bingel [31]

<em>why Is there just a random "u" in the middle of the equation </em><em>awa</em><em> </em>

<em> </em><em>t</em><em>h</em><em>e</em><em>question is impossible to do btw </em>

<em>Imao the u in the middle doesn't makes sense </em>

if<em> you edit the question I'll help you w it)</em>

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6 0
2 years ago
Read 2 more answers
What are the methods that are used for heat transfer
Roman55 [17]

Answer:

Heat can travel from one place to another in three ways: Conduction, Convection and Radiation. Both conduction and convection require matter to transfer heat. If there is a temperature difference between two systems heat will always find a way to transfer from the higher to lower system.

Explanation:

Hope this helps

6 0
3 years ago
a u tube contains a liquid of an unknown density an oil of density is poured into the right arm of the tube until the oil column
scoray [572]

Answer:

The answer is "1155\ \frac{kg}{m^3}"

Explanation:

Please find the complete question in the attached file.

p = p_0 + ?gh

pi = pressure only at two liquids' devices

PA = pressure atmosphere.

1 = oil density

2 = uncertain fluid density

h_1 = 11 \ cm\\\\h_2= 3 \ cm

The pressures would be proportional to the quantity 11-3 = 8 cm from below the surface at the interface between both the oil and the liquid.

\to p_A + ?2g(h_1 - h_2) = p_A + ? 1gh_1\\\\\to ?2 = \frac{?1h_1}{(h_1 - h_2)} \\\\

       = \frac{840 \frac{kg}{m^3}}{\frac{11}{8}} \\\\= 1155\ \frac{kg}{m^3}

8 0
2 years ago
A child slides down a hill on a toboggan with acceleration of 1.8 m/s2. if she starts from rest, how far has she traveled in:
Stells [14]

A child slides down a hill on a toboggan with acceleration of 1.8 m/s2. if she starts from rest, how far has she traveled in: 2 seconds

Answer:

2.4 m

Explanation:

From the question above,

Applying equation of motion,

s = ut+at²/2....................... Equation 1

Where t = time, u = initial velocity, a = acceleration,  s = distance.

make s the subject of the equation,

Given: a = 1.8 m/s²,  t = 2 seconds, u = 0 m/s (from rest)

Substitute these value into equation 1

s = 0(2)+1.8(2²)/2

s = 1.2(4)/2

s = 2.4 m.

Hence she has traveled 2.4 m

4 0
3 years ago
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