Question

The equation $ y=A\sin 2\pi \left( \frac{t}{T}-\frac{x}{\lambda } \right), $ where the symbols carry the usual meaning and A, T and $ \lambda $ are positive, represents a wave of:

• A. amplitude 2 A
• B. period $ T/\lambda $
• C. speed $ x\lambda $
• D. velocity in negative $ x- $ direction
• E. speed $ (\lambda /T) $

Answer 1

Answer: (E)

Speed $ v=\frac{\omega }{k}=\frac{2\pi \times \lambda }{T\times 2\lambda }=\frac{\lambda }{T} $