Explanation:
Given that,
The initial velocity of a skater is, u = 5 m/s
She slows to a velocity of 2 m/s over a distance of 20 m.
We can find the acceleration of skater. It is equal to the rate of change of velocity. So, it can be calculated using third equation of motion as follows :
[tex]v^2-u^2=2as[/tex]
a = acceleration
[tex]a=\dfrac{v^2-u^2}{2s}\\\\a=\dfrac{(2)^2-(5)^2}{2\times 20}\\\\a=-0.525\ m/s^2[/tex]
So, her acceleration is [tex]0.525\ m/s^2[/tex] and she is deaccelerating. Also, her initial velocity is given i.e. 5 m/s.
