boiiii I wont show you nun
Well, the acceleration is the difference of speeds divided by the time period.

.
One rev/s is

, so our final result is

.
Here we can use momentum conservation as in this type of collision there is no external force on it

now here we can say




now here we can say


now by coefficient of restitution
for elastic collision we know that e = 1


now by solving the two equation


also we know that

so final speed of the nail is 6.875 m/s