A wave pulse travels along a stretched string at a speed of 100 cm/s. What will be the speed in cm/s if the string's tension is quadrupled, the length halved and its mass is doubled

Respuesta :

Answer:

The new velocity of the string is 100 centimeters per second (1 meter per second).

Explanation:

The speed of a wave through a string ([tex]v[/tex]), in meters per second, is defined by the following formula:

[tex]v = \sqrt{\frac{T\cdot L}{m} }[/tex] (1)

Where:

[tex]T[/tex] - Tension, in newtons.

[tex]L[/tex] - Length of the string, in meters.

[tex]m[/tex] - Mass of the string, in kilograms.

The expression for initial and final speeds of the wave are:

Initial speed

[tex]v_{o} = \sqrt{\frac{T_{o}\cdot L_{o}}{m_{o}} }[/tex] (2)

Final speed

[tex]v = \sqrt{\frac{(4\cdot T_{o})\cdot (0.5\cdot L_{o})}{2\cdot m_{o}} }[/tex]

[tex]v = \sqrt{\frac{T_{o}\cdot L_{o}}{m_{o}} }[/tex] (3)

By (2), we conclude that:

[tex]v =v_{o}[/tex]

If we know that [tex]v_{o} = 1\,\frac{m}{s}[/tex], then the new speed of the wave in the string is [tex]v = 1\,\frac{m}{s}[/tex].