Final answer:
A book at rest with a mass of 60 kg has zero momentum, which is option A) 0 kg m/s. Momentum is the product of mass and velocity; hence a stationary object has no momentum.
Step-by-step explanation:
The momentum of a book resting on a table with a mass of 60 kg is 0 kg m/s. Momentum is defined as the product of an object's mass and its velocity (p = mv). Since the book is at rest, its velocity is zero, and therefore its momentum is also zero. The correct answer is A) 0 kg m/s.
Regarding the related information provided, momentum can change when a net force is applied to an object over a period of time as described by the impulse-momentum theorem: Δp = F Δt. For a net force of 120 N acting for 2 seconds, the change in momentum would be 240 kg·m/s, making answer D) correct for that question.
Lastly, momentum is always conserved in an isolated system without external forces, as illustrated by the collision example with two objects of equal mass.