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Papessa [141]
3 years ago
9

The half life of radium 222 is 38 seconds if you had a 12 gram sample how much would be left after 72 seconds

Physics
1 answer:
poizon [28]3 years ago
5 0
<span>3.2 grams The first thing to do is calculate how many half lives have expired. So take the time of 72 seconds and divide by the length of a half life which is 38 seconds. So 72 / 38 = 1.894736842 So we're over 1 half life, but not quite 2 half lives. So you'll have something less than 12/2 = 6 grams, but more than 12/4 = 3 grams. The exact answer is done by dividing 12 by 2 raised to the power of 1.8947. So let's calculate 2^1.8947 power = 12 g / (e ^ ln(2)*1.8947) = 12 g / (e ^ 0.693147181 * 1.8947) = 12 g / (e ^ 1.313305964) = 12 g / 3.718446464 = 3.227154167 g So rounded to 2 significant figures gives 3.2 grams.</span>
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You have two balls of equal size and smoothness, and you can ignore air resistance. One is heavy, the other is much lighter. You
motikmotik

Answer:

They will hit the ground at the same time.

Explanation:

By ignoring the opposing forces i.e. air resistant, both the heavy and light balls will fall with same acceleration due to gravity (g=9.8 m/s²) and g is independent of mass of the objects. Thus both will hit the ground at the same time.

4 0
3 years ago
Suppose that two point charges, each with a charge of +1.00 C, are separated by a distance of 1.0 m. If the distance between the
Aleksandr-060686 [28]

Given:

The magnitude of each charge is q1 = q2 = 1 C

The distance between them is r = 1 m

To find the force when distance is doubled.

Explanation:

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\begin{gathered} r^{\prime}=\text{ 2r} \\ =2\times1 \\ =2\text{ }m \end{gathered}

The force can be calculated by the formula

F=k\frac{q1q2}{(r^{\prime})^2}

Here, k is the constant whose value is

k=9\times10^9\text{ N m}^2\text{ /C}^2

On substituting the values, the force will be

\begin{gathered} F=9\times10^9\times\frac{1\times1}{(2)^2} \\ =2.25\times10^9\text{ N} \end{gathered}

7 0
1 year ago
A vector quantity must include both magnitude and direction. Which measurement is a vector quantity? A) the rain accumulation at
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Answer:

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3 years ago
Two electric charges A and B were placed facing each other at a distance of separation "r". The common electrostatic force betwe
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Answer:

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F \:  \alpha  \:  \frac{1}{ {r}^{2} }  \\  \\ F =  \frac{x}{ {r}^{2} }

x is a constant of proportionality

• when force is 4N, separation distance is 1

4 =  \frac{x}{1}  \\ x = 4

therefore, equation becomes

F =  \frac{4}{ {r}^{2} }  \\

when r is doubled, r becomes 2. find F:

F =  \frac{4}{ {2}^{2} }  \\  \\ F =  \frac{4}{4}  \\  \\ { \underline{force \: is \: 1N}}

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3 years ago
Which kind of air front forms when a warm air mass meets the area of a cooler air mass?
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<span>Answer:  "a cold front" .
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