Practice question

**Wave classification** depends on particle vibration relative to propagation. Longitudinal waves have particle oscillation parallel to propagation, creating compressions and rarefactions as in sound in air; transverse have perpendicular oscillation. Tuning fork generates longitudinal sound because air cannot sustain shear. Speed: v = (length/time) = (4/0.02) = 200 m/s . μ = (0.08/4) = 0.02 kg/m . v = √((T/μ)) ⇒ 200 = √((T/0.02)) ⇒ 200² = (T/0.02) . T = 40000 × 0.02 = 800 N . Using v = fλ and standing-wave condition fₙ = n v/(2L) or v/(4L) as applicable, calculation yields 800 N, illustrating frequency-length-speed interdependence and quantization by boundaries.