physics
posted by josh .
A 120kg 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:
friction=mu*mg
Then find the work done on friction:
mu*mg*17
Finally, find the KE of the crate
KE crate=workinfrictionwork
1/2 mv^2=400*34mu(mg)17
v^2=800*34/mass 2*mu*g*17
solve for v
check my thinking.
Respond to this Question
Similar Questions

physics
A 150 kg crate, starting from rest, is pulled across a floor with a constant horizontal force of 420 N. For the first 21 m the floor is frictionless, and for the next 21 m the coefficient of friction is 0.30. What is the final speed … 
PHYSICS
A 120kg crate, starting from rest, is pulled across a floor with a constant horizontal force of 450 N. For the first 11 m the floor is frictionless, and for the next 11 m the coefficient of friction is 0.30. What is the final speed … 
physics
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 … 
physics
A 120kg 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 … 
Physics
A 120kg 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 … 
PHYSICS HELP!
A 120kg 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 … 
Help! Physics!!
A 120kg 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 … 
physics
A 110kg crate, starting from rest, is pulled across a floor with a constant horizontal force of 420 N. For the first 13 m the floor is frictionless, and for the next 13 m the coefficient of friction is 0.35. What is the final speed … 
physics
52.(52G) A 110kg crate, starting from rest, is pulled across a floor with a constant horizontal force of 350 N. For the first 15 m the floor is frictionless, and for the next 15 m the coefficient of friction is 0.30. What is the final … 
physics
A 82.0 kg crate, starting from rest, is pulled across a floor with a constant horizontal force of 314.0 N. The floor is rough with a coefficient of friction of 0.30. What is the final speed of the crate, in m/s, after it has been pulled …