Question 1
When a crate of mass m is dragged a distance d along a surface with coefficient of kinetic friction μk, then dragged back along the same path to its original position, the work done by friction is
◦
0.
◦
−μkmgd.
◦
+μkmgd.
◦
−2μkmgd.
◦
+2μkmgd.
Question 2
When a crate of mass m is dragged a distance d along a surface with coefficient of kinetic friction μk, then dragged back along the same path to its original position, the work done by friction is
◦
0.
◦
−μkmgd.
◦
+μkmgd.
◦
−2μkmgd.
◦
+2μkmgd.