Fusion is the energy source of stars. The energy that is being released from the gas collapse into a protostar causes the center of the protostar to become extremely hot. Once the core is hot enough, nuclear fusion commences. The fusion reaction is a very structured process, releasing a huge amount of energy.
Answer:
(a) Angular acceleration will be ![\alpha =18.66rev/min^2](https://tex.z-dn.net/?f=%5Calpha%20%3D18.66rev%2Fmin%5E2)
(B) Final angular velocity will be 28 rev/min
Explanation:
We have given time t = 1.5 min
Angular displacement ![\Theta =21rev](https://tex.z-dn.net/?f=%5CTheta%20%3D21rev)
(a) Initial angular speed ![\omega _i=0rad/sec](https://tex.z-dn.net/?f=%5Comega%20_i%3D0rad%2Fsec)
From second equation of motion we know that ![\Theta =\omega _it+\frac{1}{2}\alpha t^2](https://tex.z-dn.net/?f=%5CTheta%20%3D%5Comega%20_it%2B%5Cfrac%7B1%7D%7B2%7D%5Calpha%20t%5E2)
So ![21 =0\times 1.5+\frac{1}{2}\times \alpha\times 1.5^2](https://tex.z-dn.net/?f=21%20%3D0%5Ctimes%201.5%2B%5Cfrac%7B1%7D%7B2%7D%5Ctimes%20%5Calpha%5Ctimes%20%201.5%5E2)
![42 =\alpha\times 1.5^2](https://tex.z-dn.net/?f=42%20%3D%5Calpha%5Ctimes%20%201.5%5E2)
![\alpha =18.66rev/min^2](https://tex.z-dn.net/?f=%5Calpha%20%3D18.66rev%2Fmin%5E2)
(b) Now from first equation of motion
![\omega _f=\omega _i+\alpha t=0+18.66\times 1.5=28rev/min](https://tex.z-dn.net/?f=%5Comega%20_f%3D%5Comega%20_i%2B%5Calpha%20t%3D0%2B18.66%5Ctimes%201.5%3D28rev%2Fmin)
I am not sure whether this is the right way to go about answering the question.
The resistance of a wire is proportional to its length, therefore doubling the length should double the resistance. But resistance is also proportional to the inverse square of the wire's cross-sectional area, and stretching the wire seems to imply increasing its length and decreasing its cross-sectional area, which would increase the resistance more than simply increasing its length.
I'll just say to only care about the effect of increasing the wire's length. Due to the wire's length now being 2l, the new resistance is 2r.
Answer:
800 N
Explanation:
During terminal velocity, air resistance=weight