Answer:
Inertia is the tendency or ability of a body to remain at rest or in uniform motion along a straight line in the absence of any external force. It is the reluctance a body displays when agitated or encountered by an external.
By the law of inertia, an object will always remain in its position of rest or state of uniform motion along a straight line until it is engaged with an external force.
To put it in other words;
When an object is at rest, it will want to remain at rest. If it becomes engaged with an external force it will display some reluctance before it changes its mechanical state.
Similarly, when an object is in uniform motion, it will want to continue with the motion. If an external force then interrupts it, it will also display some reluctance. This reluctance is in the form of it wanting to continue its motion irrespective of the force.
So therefore if I am moving fast on a skateboard and suddenly I become interrupted with a force, by the law of inertia my tendency is to continue the motion and this makes me exhibit reluctance in responding to the force. This reluctance will then make me to topple over and fall off if there is nothing to quickly hold unto. The more massive I am, the greater the effect of the topple. The inertia of an object is proportional to its mass.
