The brake pads for a bicycle tire are made of rubber. If a frictional force...

The base is 20 mm and 50 mm in size. The strain in the tire must be ascertained.Friction force
${\displaystyle F_t=50N}$
Using the expressed shear stress, we will determine T.
Surface cross-sectional area:
${\displaystyle A=50\cdot 20}$
${\displaystyle =1000m{m}^2}$
${\displaystyle \tau =\frac{F_t}{A}}$
${\displaystyle =\frac{50}{1000}}$
${\displaystyle \tau =0.05MPa}$
We can also calculate the shear stress in the following way.
${\displaystyle \tau =\gamma \cdot G}$
Where:
$\gamma$- shear strain
$\tau$- shear strain
${\displaystyle \Rightarrow \gamma =\frac{\tau }{G}}$
${\displaystyle =\frac{0.05}{0.20}}$
${\displaystyle \gamma =0.25rad}$
The solution is:
${\displaystyle \gamma =0.25rad}$