A Level Physics: Newton's First Law

[@The_Green_Man_OAP]

3:07 Should we be really saying "mass" is inertia or that "mass moment" is inertia? i.e mass moment:= mass*position (relative a reference) and change in mass moment= mass* change in position=momentum*time:= Inertia.

[@liveszain]

Why isn't the answer C?

[@zhelyo_physics]

Excellent question! You can have an object with zero net force and moving at constant velocity , e.g. you push a box to the left with 5N, meanwhile drag acts in the opposite direction with 5N, overall the net force is 0 but the object is moving at a constant speed.

[@The_Green_Man_OAP]

Assuming that the magnitude of the difference in internal tension (upwards vs downwards) inside the object is less than 10N then another answer is E: The object could be moving upwards AND downwards, i.e. It has been torn in two!

[@The_Green_Man_OAP]

However, if you drew applied force vectors so that they originate at the centre of mass, the net force would be zero and it would either go nowhere or continue at it's initial velocity.

[@The_Green_Man_OAP]

Yet another option would be F (assuming vacuum conditions): The object oscillates in and out, because it has elastic properties; you have increased tension inside it, therefore when released it will rebound inwards and the rebound again, but outwards...then inwards...then outwards...etc. However, this motion would be superimposed on the initial linear motion.