Nick is pulling a $20\mathrm{kg}$ crate across a horizontal floor with a rope angled 30° above the horizontal. The coefficients of kinetic and static friction are 0.2 and 0.3 respectively. If the crate is moving at a constant speed, what is the tension in the rope?

A tire swing hangs from a tree branch by a rope. Identify all the forces acting on the tire.

You push a couch across a carpeted (rough) living room floor. Identify all the forces acting on the couch.

(I) A 650-N force acts in a northwesterly direction. A second 650-N force must be exerted in what direction so that the resultant of the two forces points westward? Illustrate your answer with a vector diagram.