Answer:
8.61 min
Explanation:
original mass= 12.65
first half life = 12.65/2 = 6.325
second half life = 6.325/2 = 3.1625
Note : 3.1625 is the closest to the value (3.115) given so we work with it
total time for decay =17.22
therefore two decays = 17.22/2= 8.61
Answer:
Explanation:
I will try to use newton’s second law and its’ concept of spring. The detailed solution is shown it the documents and I also used some mathematical concept which is highlighted.
Answer:
time taken is equal to 14,156 years
Explanation:
we know,
![Y=Ae^{-kt}](https://tex.z-dn.net/?f=Y%3DAe%5E%7B-kt%7D)
at t = 0
Y(0) = A
given that half life of plutonium 239 = 24,200
![\dfrac{A}{2}=Ae^{-kt}\\0.5=e^{-kt}\\k\times 24200 = ln(2)\\k = \dfrac{ ln(2)}{24200}](https://tex.z-dn.net/?f=%5Cdfrac%7BA%7D%7B2%7D%3DAe%5E%7B-kt%7D%5C%5C0.5%3De%5E%7B-kt%7D%5C%5Ck%5Ctimes%2024200%20%3D%20ln%282%29%5C%5Ck%20%3D%20%5Cdfrac%7B%20ln%282%29%7D%7B24200%7D)
![Y=Ae^{-kt}](https://tex.z-dn.net/?f=Y%3DAe%5E%7B-kt%7D)
![\frac{3}{2} = e^{-kt}\\ln(1.5)=-\dfrac{ ln(2)}{24200}\times t\\t=-\dfrac{ln(1.5)\times 24200}{ ln(2)}\\t=14,156 \ years](https://tex.z-dn.net/?f=%5Cfrac%7B3%7D%7B2%7D%20%3D%20e%5E%7B-kt%7D%5C%5Cln%281.5%29%3D-%5Cdfrac%7B%20ln%282%29%7D%7B24200%7D%5Ctimes%20t%5C%5Ct%3D-%5Cdfrac%7Bln%281.5%29%5Ctimes%2024200%7D%7B%20ln%282%29%7D%5C%5Ct%3D14%2C156%20%5C%20years)
hence time taken is equal to 14,156 years
Answer:
-20N
Explanation:
The racquet ball will bounce back with the same force.
This is in compliance with newton's third law of motion:
"action and reaction are equal but opposite"
If the ball hits the wall with an action force of 20N, the reaction force will be -20N.
The negative indicates an oppositely directed force.