posted by josh .
A 120-kg crate, starting from rest, is pulled across a floor with a constant horizontal force of 400 N. For the first 17 m the floor is frictionless, and for the next 17 m the coefficient of friction is 0.34. What is the final speed of the crate?
find the work that went into the system: Force*distance
Now, find the frictional force on the next portion:
Then find the work done on friction:
Finally, find the KE of the crate
solve for v
check my thinking.