Answer:
Explanation:
The time that will take for nickel to decay can be calculated using the decay equation:
<u>Where:</u>
<em>N(t): is the quantity of Ni that still remains after a time t, </em>
<em>N(0): is the initial quantity of Ni </em>
<em>t: is the time </em>
<em>λ: is the decay constant of Ni </em>
The decay constant can be calculated using the half-life of Ni:
<u>Here</u>:
<em>τ is the half-life (τ = 100 y) </em>
Now, we can write N(t) in terms of N(0), because we know that nickel decay 67% after t time, in other words: N(t)=N(0)*0.67.
Therefore, we can rewrite the decay equation:
Finally, we just need to find t.
I hope it helps you!
Density = mass/volume
14 grams/42cm^3 = 1/3 or 0.333 grams/cm^3
Explanation:
from math import pi//imports the pi constant
def surf_area_sphere(rad)://naming the function and designating input argument
return 4*pi*rad**2//value to be returned
print("Enter a number: ")
rad = float(input())//collects user input
print(surf_area_sphere(rad))//calls the function
Answer:
1.505
Explanation:
cylindrical part of diameter d is loaded by an axial force P. This causes a stress of P/A, where A = πd2/4. If the load is known with an uncertainty of ±11 percent, the diameter is known within ±4 percent (tolerances), and the stress that causes failure (strength) is known within ±20 percent, determine the minimum design factor that will guarantee that the part will not fail.
stress is force per unit area
stress=P/A
A = πd^2/4.
uncertainty of axial force P= +/-.11
s=+/-.20, strength
d=+/-.04 diameter
fail load/max allowed
minimum design=fail load/max allowed
minimum design =s/(P/A)
sA/P
A=(
.96d^2)/4, so Amin=
(because the diameter at minimum is (1-0.04=0.96)
minimum design=Pmax/(sminxAmin)
1.11/(.80*.96^2)=
1.505
