Question

A 15.0 m length of steel rod expands by 4.00 mm when heated. Calculate the rise in temperature. Coefficient
linear expansion of steel is 11 X 10.6 °C!
(Ans. 2420​

Answer 1

Answer:

Let the initial lengths of the rods(at 0  

∘

C) be l  

1

​  

 and l  

2

​  

.

Since the difference in lengths at all temperatures is 30cm,

l  

2

​  

−l  

1

​  

=30

and l  

1

​  

(1+α  

1

​  

Δθ)−l  

2

​  

(1+α  

2

​  

Δθ)=30

⟹l  

1

​  

α  

1

​  

=l  

2

​  

α  

2

​  

 

⟹11l  

1

​  

=19l  

2

​  

 

and l1 −l2=30cm

⟹l1=71.25cm,l2 =41.25cm