Calculate an increase in the length of an Aluminum bar 2 m long when heated from 0°C to 20°C. The thermal coefficient of linear expansion of Aluminum is 2.5 ｘ10⁻⁵K⁻¹. Ans. (0.1cm)


Given:

Original (Initial) Length of an Aluminum bar = Lₒ = 2 m
Initial Temperature = T₁ = 0°C = (0 + 273) K = 273 K
Final Temperature = T₂ = 20°C = (20 + 273) K = 293 K
Thermal Coefficient of Linear expansion of Aluminum = 𝝰 = 2.5 ｘ10⁻⁵K⁻¹

To Find:

Increase in Length = L - Lₒ  = ?

Solution:  

The formula for an increase in length is 

L - Lₒ  = 𝝰 Lₒ ( T₂  - T₁)

by putting values 

L - Lₒ  = 2.5 ｘ10⁻⁵K⁻¹ ｘ 2 m (293 K - 273 K)

L - Lₒ  = 2.5 ｘ10⁻⁵K⁻¹ ｘ 2 (20 K)

L - Lₒ  = 2.5 ｘ10⁻⁵K⁻¹ ｘ 40 mK 

L - Lₒ  = 100 ｘ10⁻⁵ m 

L - Lₒ  = 1 ｘ10⁻³ m 

L - Lₒ  = 0.001 m 

or

L - Lₒ  = 0.1 cm 

Thus the increase in length of Aluminum after heating is 0.1 cm

************************************
************************************

Shortcut Links For 


1. Website for School and College Level Physics   
2. Website for School and College Level Mathematics  
3. Website for Single National Curriculum Pakistan - All Subjects Notes 

© 2020-21 Academic Skills and Knowledge (ASK)     

Note:  Write me in the comment box below for any query and also Share this information with your class-fellows and friends.