Four strain gauges are bonded onto a cantilever as shown in Figure 8.20(a). Given that the gauges are placed halfway along the cantilever and the cantilever is subject to a downward force of 0.5 N, use the data given below to calculate the resistance of each strain gauge:
Cantilever data Strain gauge data Length l = 25 cm Gauge factor G = 2.1
Width w = 6 cm Unstrained resistance R0 = 120 Ω
Thickness t = 3 mm
Young's modulus E = 70 × 109 Pa