Answer:
D) the decay rates of radioactive uranium and lead
Explanation:
As we know that when she found the substance it must have some fixed ratio of radioactive uranium and Lead in that substance.
Here since Uranium is radioactive substance so it will continuously convert into Lead and this ratio will change with time
So here we can say that the ratio of radioactive uranium and lead will depend on its decay rate
now to find the age of the substance we can find the present ratio of lead and uranium in that substance and then compare it with freshly prepared substance.
so by the formula
we can find the age of the sample
A 300-kg bear grasping a vertical tree slides down at constant velocity. The friction force between the
tree and the bear is
Answer:
Explanation:
pV = nrT
n = PV/RT
n = (100*10^3)(.01)/(300*0.082057)
n = 40.62 moles
The law of equal areas suggests that planets move fastest when at "perihelion" at slowest when at the "aphelion." Perihelion refers to the point at a planet's orbit, comet or asteroid where it is closest to the sun. Aphelion <span>refers to the point at a planet's orbit, comet or asteroid where it is furthest to the sun.</span>
