Volumetric flasks are most accurate
The equivalent resistance of n resistors in series is given by:

In our circuit, we have three resistors of

each, therefore the equivalent resistance of the circuit is
Answer:
- 0.09 % of the original radioactive nucllde its left after 10 half-lives
- It will take 241,100 years for 10 half-lives of plutonium-239 to pass.
Explanation:
The equation for radioactive decay its:
,
where N(t) its quantity of material at time t,
its the initial quantity of material and
its the mean lifetime of the radioactive element.
The half-life
its the time at which the quantity of material its the half of the initial value, so, we can find:

so:




So, after 10 half-lives, we got:




So, we got that a 0.09 % of the original radioactive nucllde its left.
Putonioum-239 has a half-life of 24,110 years. So, 10 half-life will take to pass

It will take 241,100 years for 10 half-lives of plutonium-239 to pass.
Explanation:
All the energy in oil, gas, and coal originally came from the sun captured through photosynthesis. In the same way that we burn wood to release energy that trees capture from the sun, we burn fossil fuels to release the energy that ancient plants captured from the sun.
Average speed = (total distance) / (total time)
Total distance = (70km + 104km + 79km) = 253 km
Total time = (2hr + 1.5hr + 2hr) = 5.5 hrs
Average speed = (253 km) / (5.5 hrs)
<em>Average speed = 46 km/hr</em>