Chapter 4 - Force and Motion - Learning Path Questions and Exercises - Exercises - Page 135: 8

a. Either one or two is possible b. Yes

a. acceleration being 0 means that the objects velocity is not changing. This could mean that the object has a constant velocity, which also gives it the possibility that the velocity can be 0. Therefore both one and two are possible. b. Yes, there is a third force. Since both forces have the same magnitude but are not directly opposite each other, there has to be a third force to keep the object at rest.