An aluminium alloy used for making cans is cold rolled into a strip of thickness 0.3mm and width 1m. It is coiled round a drum of diameter 15cm, and the outer diameter of the coil is 1m. In the cold rolled condition, the dislocation density is approximately 1015 m-2. Estimate: (i) The mass of aluminium on the coil; (ii) The total length of strip on the coil; (iii) The total length of dislocation in the coiled strip.

Respuesta :

Answer:

1. Mass = 2070 kg

2.Total length of strip = 2556 m

3. Total length of dislocation = 7.67 X[tex]10^{14}[/tex] m

Explanation:

Given:

Aluminium coil thickness, t = 0.3 mm

                                              = 0.3 X [tex]10^{-3}[/tex] m

Width of the coil,w = 1 m

Drum diameter, d = 15 cm

                              = 0.15 m

Coil outer diameter, d = 1 m

Dislocation density = [tex]10^{15}[/tex] [tex]m^{2}[/tex]

1). Area of the coil, A = [tex]\frac{\pi }{4}\times[/tex] ( [tex]d_{coil} ^{2}[/tex]-[tex]d_{drum} ^{2}[/tex])

                           A = [tex]\frac{\pi }{4}\times (1^{2}-0.15^{2})[/tex]

                           A = 0.767 [tex]m^{2}[/tex]

Volume of the coil,V = A X w

                                  = 0.767 X 1

                                  = 0.767 [tex]m^{3}[/tex]

We know density of aluminum at STP = 2.7 X [tex]10^{3}[/tex]

Therefore, mass of the aluminum coil is,

Mass,m = Density of aluminium X Volume

             = 2.7 X [tex]10^{3}[/tex] X 0.767

             = 2070 kg

Mass = 2070 kg

2). Total length of trip of coil is given by

          L = Volume of coil / area of strip

             = [tex]\frac{0.767}{1\times 0.3\times 10^{-3}}[/tex]

              = 2556 m

Total length of strip = 2556 m

3). Total length of dislocation of the coiled strip = volume X dislocation density

                                                                             = 0.767 X [tex]10^{15}[/tex]

                                                                              = 7.67 X [tex]10^{14}[/tex]

Total length of dislocation = 7.67 X[tex]10^{14}[/tex] m