Machine-translated by Google. Questions are authored in English.
Top

Discussion

In the given wave equation y=0.05 \(\sin\frac{2\pi}{\lambda}\) (x-200t) m, the velocity of the wave (in ms-1) is

  • A.\(2\sqrt{200}\)
  • B.400
  • C.\(200\sqrt{2}\)
  • D.\(2\sqrt{300}\)
  • E.200

Answer: E

The wave velocity is 200 m s-1.

A travelling wave of the form \(y = A\sin\frac{2\pi}{\lambda}(x - vt)\) moves in the positive x-direction with speed \(v\). Comparing with \(y = 0.05\sin\frac{2\pi}{\lambda}(x - 200t)\) gives \(v = 200\) m s-1 directly.

Equivalently, \(k = \frac{2\pi}{\lambda}\) and \(\omega = \frac{2\pi}{\lambda} \times 200\), so \(v = \frac{\omega}{k} = 200\). The square-root options have no basis in this equation, and 400 doubles the speed.

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.