Answer:
190 كم / ساعة ، 64 درجة جنوب شرق
Explanation:
<span>Cobalt-60 is undergoing a radioactivity decay.
The formula of the decay is n=N(1/2)</span>∧(T/t).
<span>Where N </span>⇒ original mass of cobalt
<span> n </span>⇒ remaining mass of cobalt after 3 years
T ⇒ decaying period
t ⇒ half-life of cobalt.
So,
0.675 = 1 × 0.5∧(3/t)
log 0.675 = log 0.5∧(3/t)
3/t = log 0.675 ÷log 0.5
3/t= 0.567
t = 3÷0.567
= 5.290626524
the half-life of Cobalt-60 is 5.29 years.
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<span>In an experiment, the non-charged balloon moves towards the charged rod. this is applicable with the spheres.
Suppose the sphere is positively charged, the neutrally charged sphere becomes is negatively charged. The positively charged sphere causes the other sphere to be polarized, with negative charge on the side closest to the first sphere. Now the second sphere moves towards the first sphere. answer is A.</span>
Option D. The mechanical layer of Earth that has the most active convection currents is Asthenosphere.
<h3>What is Asthenosphere?</h3>
The asthenosphere is the mechanically weak and ductile region of the upper mantle of Earth.
The asthenosphere, zone of Earth's mantle lying beneath the lithosphere and believed to be much hotter and more fluid than the lithosphere. It is the most active layer for convection current.
Thus, the mechanical layer of Earth that has the most active convection
currents is Asthenosphere.
Learn more Asthenosphere here: brainly.com/question/26271915
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