Answer:
A sample of 5.2 mg decays to .65 mg or to 1/8 of its original amount.
1/8 = 1/2 * 1/2 * 1/2 or 3 half-lives.
3 * 30.07 = 90 yrs for 5.2 mg to decay to .65 mg
You can get these other numbers similarly:
5.2 / .0102 = 510 requires about 9 half-lives which is 30 * 9 = 270 yrs
Answer:
Explanation:
It is given that three cars has same mass m with speed
suppose rest two cars also has same mass m
As there is no external force therefore momentum is conserved
Initial Momentum 
Final momentum 
where v=final velocity
thus final velocity is
Answer:
the answer to this question is
<em>The</em><em> </em><em>Same</em><em> </em>
<em>newton's</em><em> </em><em>law</em><em> </em><em>#3</em>
Explanation:
<em>Hope</em><em> </em><em>this</em><em> </em><em>helps</em><em> </em>
Answer: the body is trained to wake up when the sun rises and get the energy from the sun and sleep and it is night on when the sun is not there. So when a watchman works at night there is no sun first of all to give him any kind of energy and secondly the body clock resists him waking up thus making him tired.
Explanation:
<u>Answer</u>
Gravitational force
<u>Explanation</u>
Gravitational force is the force of attraction between two bodies of a given masses. It is calculated as follows:
Gravitational force = GM₁M₂/r²
From the formula it can be seen that gravitational force is inversely proportional to the r where are is the distance between the two bodies.
When the distance increases the gravitational force decreases.
