The speed \( v \) of a wave is related to its frequency \( f \) and wavelength \( \lambda \) by the equation: \[ v = f \times \lambda \] where:
- \( f = 600 \, {Hz} \) is the frequency of the wave,
- \( \lambda = 0.5 \, {m} \) is the wavelength.
Substituting the values: \[ v = 600 \times 0.5 = 300 \, {m/s} \] Now, to find the time \( t \) it takes for the wave to travel a distance of 200 m, we use the equation: \[ v = \frac{{distance}}{{time}} \quad \Rightarrow \quad t = \frac{{distance}}{v} \] Substitute the values: \[ t = \frac{200}{300} = 0.67 \, {s} \] Thus, the time taken for the wave to travel 200 m is \( 0.67 \, {s} \).
Therefore, the correct answer is option (B), 0.67 s.
The focus of the parabola \(y^2 + 4y - 8x + 20 = 0\) is at the point:
Let \( S \) denote the set of all subsets of integers containing more than two numbers. A relation \( R \) on \( S \) is defined by:
\[ R = \{ (A, B) : \text{the sets } A \text{ and } B \text{ have at least two numbers in common} \}. \]
Then the relation \( R \) is:
The centre of the hyperbola \(16x^2 - 4y^2 + 64x - 24y - 36 = 0\) is at the point: