A) \[\frac{\pi }{3}\]
B) \[\frac{\pi }{2}\]
C) \[\frac{\pi }{6}\]
D) \[\pi \]
Correct Answer: B
Solution :
\[y=10\sin \left[ \frac{2\pi }{45}t+\alpha \right]\] \[y=5cm\,at\,t=0\] \[\therefore \] \[5=10(sin\alpha )\] or \[sin\alpha =\frac{1}{2}\] or \[\alpha =\frac{\pi }{6}\] Again if t =7.5s Then total phase \[=\frac{2\pi }{45}\times \frac{15}{2}+\frac{\pi }{6}\] \[=\frac{\pi }{3}+\frac{\pi }{6}\] \[=\frac{2\pi +\pi }{6}+\frac{3\pi }{6}=\frac{\pi }{2}\]You need to login to perform this action.
You will be redirected in
3 sec