A piano wire of length 50 cm and mass of 6.5 gm is stretched so that t...
To determine the stretching force on a piano wire given its dimensions and frequency of vibration, we can use the relationship between the frequency, tension, length, and mass per unit length of the wire.
Given Parameters- Length of the wire (L): 50 cm = 0.5 m
- Mass of the wire (m): 6.5 gm = 0.0065 kg
- Frequency of fundamental mode (f): 80 cycles/sec
Calculating Mass per Unit Length- The mass per unit length (μ) can be calculated using:
- μ = m / L
- μ = 0.0065 kg / 0.5 m = 0.013 kg/m
Using the Frequency Formula- The frequency of the fundamental mode for a stretched wire is given by:
- Rearranging to find tension (T):
Substituting Values- Now, substituting the values into the equation:
- T = (2 * 0.5 m * 80 Hz)² * 0.013 kg/m
- T = (80 m/s)² * 0.013 kg/m
- T = 6400 * 0.013 = 83.2 N
Converting Tension to gm-wt- To convert the tension from Newtons to gram-force (gm-wt):
- 1 N = 101.97 gm-wt
- Force in gm-wt = 83.2 N * 101.97 gm-wt/N = 8476.784 gm-wt
Final Result- The stretching force in the wire is approximately
8476.78 gm-wt.