Answer the following.
  
1. A Solid has a area A1 at temperature T1. The temperature is increased to T2. If βis the coefficient of superficial expansion, the increase in area is given by ___________.
 
 
2. Some aluminum has a coefficient of linear expansion of 25×106K1. A 100\(mm\) length of aluminum piping is heated through 50\(K\). The pipe extends by  .