The equation of a stationary wave is y = 0.8 cos πx20sin 200 πt where x is in cm and t is in s. The separation between consecutive nodes will be

Standard equationy=A cos 2πxλ sin 2πvtλBy comparing this equation with given equation.2πxλ=πx20      ⇒   λ=40 cmDistance between two nodes = λ/2 = 20 cm