Login/Sign Up
Home » An equilateral triangle ABC is formed by two Cu rods AB and BC and one Al rod. It is heated in such a way that the temperature of each rod increases by ∆T. Find the change in the angle ABC.
An equilateral triangle ABC is formed by two Cu rods AB and BC and one Al rod. It is heated in such a way that the temperature of each rod increases by ∆T. Find the change in the angle ABC.
CBSE | Class 11 | Mechanical Properties of Solids | NCERT Exemplar | Physics
An equilateral triangle ABC is formed by two Cu rods AB and BC and one Al rod. It is heated in such a way that the temperature of each rod increases by ∆T. Find the change in the angle ABC.

Answer :

The change in angle ABC is calculated using trigonometry.
\cos \theta =\frac{l_{1}^{2}+l_{3}^{2}-l_{2}^{2}}{2{{l}_{3}}{{l}_{1}}}

The change in angle ABC is given as when the above equation is differentiated.

d\theta =\frac{2\left( {{\alpha }_{2}}-{{\alpha }_{1}} \right)\Delta T}{\sqrt{3}}

 

i

More Material