Answer:
Explanation:
Due to heat energy , metal expands . Formula for linear expansion is as follows .
L = l ( 1 + α Ît )
where L is expanded length , l is original length , α is coefficient of linear expansion and Ît is increase in temperature .
To pass the sphere through the ring , the diameter of both ring and sphere should be same after heating . Let after increase of temperature Ît , their diameter becomes same as L Â . The linear coefficient of brass and steel are
20 x 10â»â¶ and 12 x 10â»â¶ respectively .
For steel sphere ,
L = 25 ( 1 + 12 x 10â»â¶ Ît )
For brass ring
L = 24.9 ( 1 + 20 x 10â»â¶ Ît )
25 ( 1 + 12 x 10â»â¶ Ît ) = 24.9 ( 1 + 20 x 10â»â¶ Ît )
1.004( 1 + 12 x 10â»â¶ Ît ) =  ( 1 + 20 x 10â»â¶ Ît )
1.004 + 12.0482 x 10â»â¶ Ît  =  1 + 20 x 10â»â¶ Ît
.004 = 7.9518 x 10â»â¶ Ît
Ît  = 4000 / 7.9518
= 503â°C.
final temp = 503 + 15 = 518â°C Â .