Answer:
The new self inductance is 3 times of the initial self inductance.
Explanation:
The self inductance of a solenoid is given by :
![L=\dfrac{\mu_oN^2 A}{L}](https://tex.z-dn.net/?f=L%3D%5Cdfrac%7B%5Cmu_oN%5E2%20A%7D%7BL%7D)
Where
N is number of turns per unit length
A is area of cross section
l is length of solenoid
If length and number of coil turns are both tripled,
l' = 3l and N' = 3N
New self inductance is given by :
![L'=\dfrac{\mu_oN'^2 A}{L'}\\\\=\dfrac{\mu_o(3N)^2 A}{3L}\\\\=3\dfrac{\mu_oN^2 A}{L}\\\\=3L](https://tex.z-dn.net/?f=L%27%3D%5Cdfrac%7B%5Cmu_oN%27%5E2%20A%7D%7BL%27%7D%5C%5C%5C%5C%3D%5Cdfrac%7B%5Cmu_o%283N%29%5E2%20A%7D%7B3L%7D%5C%5C%5C%5C%3D3%5Cdfrac%7B%5Cmu_oN%5E2%20A%7D%7BL%7D%5C%5C%5C%5C%3D3L)
So, the new self inductance is 3 times of the initial self inductance.
Answer:
Explanation:
She's correct but doesn't mean the wagon cannot put into motion. The force that she applied on the wagon, according to Newton's 2nd law, would have generated an acceleration, which translates into motion. The reaction force the wagon applies on her due to Newton's 3rd law, would not hinder its own motion.
It depends on the direction in which the shell is launched. The time can be anything from 3.6 seconds to never.