\(u=5cos\left(6\pi t-\pi x\right)\)
\(\Delta\varphi=\dfrac{2\pi}{\lambda}=\pi\Rightarrow\lambda=2m\)
\(T=\dfrac{2\pi}{\omega}=\dfrac{2\pi}{6\pi}=\dfrac{1}{3}\)\(\Rightarrow f=\dfrac{1}{T}=3Hz\)
Vận tốc truyền sóng;
\(v=\lambda\cdot f=2\cdot3=6\)m/s
Chọn B
u=5cos(6πt−πx)u=5cos(6πt−πx)
T=2πω=2π6π=13T=2πω=2π6π=13