A body starts to slide over a horizontal surface with an initial velocity of $0.5\mathit{ m}/s$. Due to friction, its velocity decreases at a rate of $0.05\mathit{ m}/s^2$. Find the time taken by the body to stop.

Initial velocity, $\mathit{u }= 0.5\mathit{ m}/s$
Final velocity, $\mathit{v }= 0\mathit{ m}/s$
Acceleration, $\mathit{a }= - 0.05\mathit{ m}/s^2$ (as the velocity of the body is decreasing)
Using the first equation of motion,
$\mathit{v }=\mathit{ u }+\mathit{ at}$ $\Rightarrow 0 = 0.5 + (-0.05) \times \mathit{ t}$ $\Rightarrow \mathit{ t }= 0.5/0.05\mathit{ s }$
$\Rightarrow \mathit{ t}= 10\mathit{ s}$  

The time will it take the body to stop is $10\mathit{ s}$.