We decided that we wanted to demenstate Newtons third law of motion: For every action there is an equal or opposite reaction. This car is suppose to demenstarte the 3rd law becuase when you blow the balloon (this the action) it will make the car move foward because the air will be let out of the straw (that is the opposite reaction)
The other laws are:
Newtons 1st law: states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force.
Newtons 2nd law: states that the accererlation of an object as produced by a net force is directly proportional to the magnitude of the bet force. F=ma