By Jessica A.

"An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force."
 
 
 
*This is a diagram of the main ideas of Newton's First Law.*
   
 

This law is also called the law of Inertia. The main idea of this law is that if there is no net force (a vector sum of all the different forces acting upon an object), then this means that the object will remain at a constant velocity. This means the object will
continue to move in the same direction at the same speed. If the constant velocity of the object is 0N, then the object will remain at rest. If an additional force is exerted upon the object (causing the forces to become unbalanced), then the object will accelerate.
Basically an easier way to describe it is to say that the object will carry on doing what it was already doing unless an unbalanced force acts upon it.
   
 

An example of this is if you imagine yourself in a car speeding along a road, which then brakes to a stop suddenly. The car’s state of motion has changed because its speed has decreased, but there will be no unbalanced forces to change your state of motion. This
means that your body will continue in its state of motion, therefore sliding off the edge of your seat until the unbalanced force (the seatbelt) acts upon you preventing you from flying through the windscreen.
 
 

When an airplane is flying through the air, the thrust and drag need to be equal in size to maintain a constant speed. If the thrust is increased, then this will mean that the air speed is also increased, causing the drag to increase as well. If the thrust decreases
on the other hand, then the air speed will also decrease and the drag will decrease as well.

  
 

Imagine you are on a skateboard which stops suddenly once it hits the edge of a curb. The motion of the skateboard has stopped, but because you aren’t physically attached to the skateboard, you will continue in the previous motion you were going with on the
skateboard before it stopped. This will cause you to fly off the skateboard in the same motion.