A) 4s
B) 2s
C) 8s
D) 10s
Correct Answer: B
Solution :
Kinetic energy \[KE=\frac{1}{2}I{{\omega }^{2}}\] \[\Rightarrow \] \[\omega =\sqrt{\frac{2KE}{I}}=\sqrt{\frac{2\times 1500}{1.2}}\] \[\Rightarrow \] \[\omega =50\,rad/s\] Now \[\omega ={{\omega }_{0}}+\alpha t=0+\alpha t\] \[\Rightarrow \] \[\omega =\alpha t\] \[\therefore \] \[t=\frac{\omega }{\alpha }=\frac{50}{25}=2s\]You need to login to perform this action.
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