Question Detail

PHY 104 Wave and sound Objective Question

Question

For a standing wave described by y = 2Acos(ωt)sin(kx), the document defines nodes as points where the displacement is always zero. It specifies that for nodes, kx = nπ, where n is an integer. Given that k = 2π/λ, what are the positions of the nodes?
Options
A <i>x = nλ</i>
B <i>x = nλ/2</i>
Correct Answer
C <i>x = nλ/4</i>
D <i>x = n(2π)</i>
Correct Answer

Option B is the correct answer.

Detailed Explanation

According to page 9 of the document, nodes occur when kx = nπ, where n = 0, 1, 2, .... Substituting k = 2π/λ into this equation: (2π/λ)x = nπ. Solving for x, we get x = nπ * (λ/2π) = nλ/2. This is consistent with the 'nodes' discussion on page 9.

Hint

Substitute the expression for k in terms of λ into the condition for nodes, kx = nπ, and solve for x.

Question Info