To make a secure fit, rivets that are larger than the rivet hole are often used and the rivet is cooled (usually in dry ice) before it is placed in the hole. a steel rivet 1.870 cm in diameter is to be placed in a hole 1.868 cm in diameter in a metal at 25°c. to what temperature must the rivet be cooled if it is to fit in the hole? express your answer using two significant figures.

-63.98° C

Explanation:

Initial diameter of rivet d = 1.873 cm

Hole diameter   d ' = 1.871 cm

Coefficient of linear expansion of steel α = 12×10 -6 /° C

Initial temperature t = 25° C

We know α = ( d' - d ) / [ d ( t ' - t ) ]

          t ' - t = ( d ' - d ) / [ d x α ]

putting values we get

             t ' - t = -88.98° C

              t ' = -88.98° C + t

                  = -63.98° C

The temperature must the rivet be cooled if it is to fit in the hole (at 25°C) is -63.98° C

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