$\mathrm{Mg}=100 \mathrm{N} ; 100=\mathrm{m} \times 10 \times \frac{1}{2}$
$M=10 \mathrm{kg}, \mathrm{m}=20 \mathrm{kg}$
$\frac{m}{M}=2$
$y = \frac{{10}}{\pi }\,\sin \,\left( {\frac{{2\pi }}{T}t - \frac{{2\pi }}{\lambda }x} \right)$
For what value of the wavelength the wave velocity is twice the maximum particle velocity ..... $cm$ ?


$(i)\,\,\,\,\,{y_1} = A\,\cos \,\,2\pi \,\left( {{n_1}t\, + \,\frac{x}{{{\lambda _1}}}} \right)$
$(ii)\,\,\,\,\,{y_2} = A\,\cos \,\,2\pi \,\left( {{n_1}t\, + \,\frac{x}{{{\lambda _1}}} + \pi } \right)$
$(iii)\,\,\,\,\,{y_3} = A\,\cos \,\,2\pi \,\left( {{n_2}t\, + \,\frac{x}{{{\lambda _2}}}} \right)$
$(iv)\,\,\,\,\,{y_4} = A\,\cos \,\,2\pi \,\left( {{n_2}t\, - \,\frac{x}{{{\lambda _2}}}} \right)$
The pairs of waves which will produce destructive interference and stationary waves respectively in a medium, are