Answer:
puck decelerates due to the kinetic frictional force μk mg
Explanation:
given data
total distance = 12 m
coefficient of kinetic friction = 0.28
solution
we will apply equation of motion that is
v² - u² = 2 × a × s   ................1
we know acceleration will be
a = [tex]\frac{-u^2}{2\times S}[/tex] Â
Then we have
Force = mass × acceleration  .................2
m × [tex]\frac{-u^2}{2\times S}[/tex] = -μk mg
The puck decelerates due to the kinetic frictional force μk mg Â
and frictional force is negative as it opposes the motion.
so we get initial velocity of the puck which is strike.