机械波的计算题 A pulse of width 32.6 cm bouncing back and forth on a stretched string oflength 25.7m and mass per unit length μ = 1.65 × 10−3 kg/m is observed totake 12.8 s to make 13 round trips.What is the tension on the string?

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机械波的计算题 A pulse of width 32.6 cm bouncing back and forth on a stretched string oflength 25.7m and mass per unit length μ = 1.65 × 10−3 kg/m is observed totake 12.8 s to make 13 round trips.What is the tension on the string?

机械波的计算题 A pulse of width 32.6 cm bouncing back and forth on a stretched string oflength 25.7m and mass per unit length μ = 1.65 × 10−3 kg/m is observed totake 12.8 s to make 13 round trips.What is the tension on the string?
机械波的计算题
A pulse of width 32.6 cm bouncing back and forth on a stretched string of
length 25.7m and mass per unit length μ = 1.65 × 10−3 kg/m is observed to
take 12.8 s to make 13 round trips.What is the tension on the string?

机械波的计算题 A pulse of width 32.6 cm bouncing back and forth on a stretched string oflength 25.7m and mass per unit length μ = 1.65 × 10−3 kg/m is observed totake 12.8 s to make 13 round trips.What is the tension on the string?
并不是很确定脉冲的宽度的影响,但是弦线的两端是固定的,脉冲的宽度并不会增加波走过的距离.
走过的距离为13*2*25.7=668.2(m),时间为12.8(s)由此得到波速v=52.2 m/s.
再由弦线上的波速公式v=√(T/μ),此处μ为弦线的线质量密度.
T=v^2 *μ=(52.2)^2 *1.65×10-3=4.5(N)