Which of the following describes inertia

a balanced force
the opposite of velocity
an unbalanced force
a resistance to change in motion

Question

Which of the following describes inertia

a balanced force
the opposite of velocity 
an unbalanced force 
a resistance to change in motion

jim_thompson5910 · Answer

hint: something at rest will stay at rest

something in motion will stay in motion

this is assuming there are no external forces

anonymous · Answer

a resistance to change in motion

anonymous · Answer

So which would then be an example

a moving car changes direction
a balanced force is applied to a bike
increasing the velocity of a train make it harder to stop
adding mass to a moving car its harder to stop

please help so lost