A Newton car demonstrates Newton’s third law of motion, namely the law of interaction: For each action, there is an equal and opposite reaction. The car does this by hurling a weight off the back, forcing itself forward. This is a demonstration of how rockets are propelled in space, ejecting something that was initially internal. (This experiment also illustrates his second law of motion:Force equals mass times acceleration.)
Through the use of small wooden cars, this activity demonstrates Newton's third law of motion—which states that every action has an equal and opposite reaction. The "Newton rocket cars" that students put together show how action/reaction works and how the mass of a moving object affects the acceleration and force of the system. Subsequently, the Newton cars provide students with an excellent analogy for how rockets work.
Engineers often build models to demonstrate and study the physical laws of science as they apply in different situations and applications. Engineers who design rockets might even experiment with a small wooden car to understand Newton's third law of motion. Such a car must obey the laws of motion, just as a rocket must. Observing how a toy wooden car moves forward when a small block is launched off its back is analogousto a rocket moving forward when hot gases are expelled from the back of the rocket. By studying the similarities and differences between a small model and a real-world rocket, engineers can successfully build rockets using what they learned from their experimental model demonstrations.
OBSERVATION: On connecting the battery and placing it on the plane surface you will observe that the fan blade rotates and the car starts moving forward. You’ll be able to get the car to move forwards and backwards. Directionthe car moves will depend on what direction the motor is spinning. If your Carmoves backward, interchange +ve –ve connections.
HOW IT WORKS: This happens because of Newton’s third law of motion Newton's Third Law of Motion (law of reciprocal actions) states: "Every action has an equal and opposite reaction" i.e. Action and reaction are equal in magnitude and opposite in direction. Here the motion of the fan cuts the air which createsforce on the back side and this force the car to move forward. Hence the car moves. A propeller is a type of fan that transmits power by converting rotational motion into thrust. A pressure difference is produced between the forward and rear surfaces of the airfoil-shaped blade, and a fluid (such as air or water) is accelerated behind the blade. …
In Newton’s Car, propeller works as a wing, it produces lift, but in a forward direction—a force we refer to as thrust. Its rotary motion through the air creates a difference in air pressure between the front and back surfaces of its blades.In order for a propeller blade to spin, it usually needs the help of an engine.