Answer:
![B_2 = 1.71 mT](https://tex.z-dn.net/?f=B_2%20%3D%201.71%20mT)
Explanation:
As we know that the magnetic field near the center of solenoid is given as
![B = \frac{\mu_0 N i}{L}](https://tex.z-dn.net/?f=B%20%3D%20%5Cfrac%7B%5Cmu_0%20N%20i%7D%7BL%7D)
now we know that initially the length of the solenoid is L = 18 cm and N number of turns are wounded on it
So the magnetic field at the center of the solenoid is 2 mT
now we pulled the coils apart and the length of solenoid is increased as L = 21 cm
so we have
![\frac{B_1}{B_2} = \frac{L_2}{L_1}](https://tex.z-dn.net/?f=%5Cfrac%7BB_1%7D%7BB_2%7D%20%3D%20%5Cfrac%7BL_2%7D%7BL_1%7D)
now plug in all values in it
![\frac{2.0 mT}{B_2} = \frac{21}{18}](https://tex.z-dn.net/?f=%5Cfrac%7B2.0%20mT%7D%7BB_2%7D%20%3D%20%5Cfrac%7B21%7D%7B18%7D)
![B_2 = 1.71 mT](https://tex.z-dn.net/?f=B_2%20%3D%201.71%20mT)
Answer:
The force acting on the ball is 92.4 N.
Explanation:
Given that,
Initial speed of the ball, u = 0
Final speed of the ball, v = 31.6 m/s
The average power generated during the serve is 2920 W. Power generated by an object is given by :
![P=\dfrac{W}{t}](https://tex.z-dn.net/?f=P%3D%5Cdfrac%7BW%7D%7Bt%7D)
W is the work done, W = Fd
![P=\dfrac{Fd}{t}](https://tex.z-dn.net/?f=P%3D%5Cdfrac%7BFd%7D%7Bt%7D)
Since, ![v=\dfrac{d}{t}](https://tex.z-dn.net/?f=v%3D%5Cdfrac%7Bd%7D%7Bt%7D)
So,
![P=F\times v](https://tex.z-dn.net/?f=P%3DF%5Ctimes%20v)
F is the force acting on the ball
![F=\dfrac{P}{v}\\\\F=\dfrac{2920\ W}{31.6\ m/s}\\\\F = 92.4\ N](https://tex.z-dn.net/?f=F%3D%5Cdfrac%7BP%7D%7Bv%7D%5C%5C%5C%5CF%3D%5Cdfrac%7B2920%5C%20W%7D%7B31.6%5C%20m%2Fs%7D%5C%5C%5C%5CF%20%3D%2092.4%5C%20N)
So, the force acting on the ball is 92.4 N. Hence, this is the required solution.
Answer:
The answer is 576.0473
Explanation:
Hope this helps.
Please mark my answer as brainliest?
They both make a thing go faster and slower but the relationship is force.