True or False? why?
a.)it's possible to have motion in the absence of a force?
b.)if an object isn't moving, no external force acts on it?
c.)if an object is not acceleration, no external force is acting on it.
d.)if the net force acting on an object is in the positive x-direction, the object moves only in the positive x-direction.
Comments
a) yes it is possible to have motion with constant velocity in absence of a net force, Newton's first law says that motion with constant velocity is as natural state as rest is
b) false, there might be a force acting, but the net force is zero
c) false again, same as in c
d) true, direction of the net force = direction of motion
S was doing so well until she got to d.
d is false. If the net force acting on an object is in the positive x-direction then the accleration is in the positive x-direction. The velocity isn't neccesarily in this direction though.
a) true in space it will move without any force
b)false gravity is pulling it down to the earth
c)false gravity is still pulling it
d)false if thrown up gravity will eventually pull it down