What forces are included in a free-body diagram for an object?
a. The forces acting on the object and the forces the object exerts on any other objects it is in contact with.
b. The forces acting on the object and the forces the object exerts on all other objects in the system.
c. Only the forces acting on the object.
d. Only forces internal to the object.
Question 2
A crate of weight w is being pushed across a horizontal surface by a force directed at an angle of 20 below the horizontal. What is the magnitude of the normal force on the crate?
a. It is less than w.
b. It equals w.
c. It is more than w.
d. None of the above since the coefficient of kinetic friction is not given.