Question

1) A solid rectangular block of copper 5cm by 4cm by 2cm is drawn out to make a cylindrical wire of diameter 2 mm. Calculate the length of wire.

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Answer 1

volume of rectangular block=(5*4*2)cm3
=40cm3
diameter of cylindrical wire =2mm
therefore radius=1mm=1/10cm
since, volume of rectangular block =volume of cylindrical vessel
40cm3 =π×1/10*1/10*h cm3
40=π×h/100
40=3.14*h/100
40=314/10000*h
h=400000/314
h=1273.885 cm