Question 287: Properties of Matter

Question

Wires W1 and W2 are made of same material having the breaking stress of 1.25 $$	imes$$ 109 N/m2. W1 and W2 have cross-sectional area of 8 $$	imes$$ 10$$-$$7 m2 and 4 $$	imes$$ 10$$-$$7 m2, respectively. Masses of 20 kg and 10 kg hang from them as shown in the figure. The maximum mass that can be placed in the pan without breaking the wires is ____________ kg. (Use g = 10 m/s2)

Accepted Answer

B.S
1
= $${{{T_{1\max }}} \over {8 	imes {{10}^{ - 7}}}}$$ $$\Rightarrow$$ T
1 max
= 8 $$	imes$$ 1.25 $$	imes$$ 100 = 1000 N
B.S
2
= $${{{T_{2\max }}} \over {4 	imes {{10}^{ - 7}}}}$$ $$\Rightarrow$$ T
2 max
= 4 $$	imes$$ 1.25 $$	imes$$ 100 = 500 N
m = $${{500 - 100} \over {10}} = 40$$ kg

Properties of Matter

Choose the correct answer: