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