Objective
The objective of the experiment was to illustrate and describe action and reaction forces involved in the propulsion of devices using Newton’s third law.
Testing Newton’s third law with a balloon
Hypothesis
If the nozzle of the inflated balloon is released, it will become deflated and move in the opposite direction of the nozzle.
Procedure
A balloon was inflated by blowing up, and the nozzle was held tightly with fingers.
The nozzle was released to force out the air inside it, and observation was made.
Results
When the balloon was blown up, it became inflated, but when the nozzle was released, the balloon became deflated and moved in the opposite direction of the nozzle.
Discussion
The inflated balloon has two forces acting on its walls, which are action and reaction forces. The action force is the air pressure acting on the inside walls of the balloon while the reaction force is the atmospheric pressure acting on the outside walls of the balloon. When the inflated balloon was released, the action force comprised the release of air inside the balloon and subsequent contraction of the balloon while the movement of the balloon in the opposite direction constituted the reaction force. Thus, the results of the experiment support the hypothesis that if the nozzle of the inflated balloon is released, it will become deflated and move in the opposite direction of the nozzle because of the expulsive force of the released air.
Testing Newton’s third law with a can
Hypothesis
If a water-filled can is lifted, the one with holes will let out water and rotate faster than the one without holes.
Procedure
A can of soda was filled with water and tied with a strong thread.
The can was then lifted with the thread and its motion was observed.
The can was made steady and released carefully while observing.
The can was emptied and four holes were made around the bottom using a hammer and a sharp nail.
The can was then filled with water and lifted with the thread.
An observation was made on the motion of the can.
Results
When the can filled with water was lifted with the thread, it swung and rotated slowly. When the can was made steady and released, it fell to the ground.
When the water-filled can with holes was lifted, the water in it moved out through the holes and rotated rapidly.
Discussion
When a can filled with water was lifted, action and reaction forces acted on it. The action force is the gravitational force pulling the can towards the ground while the centripetal force is the reaction force making the can swing. Comparatively, when the water-filled can with holes was lifted, the water moved out through the holes while rotating rapidly. Therefore, the results support the hypothesis that if a water-filled can is lifted, the one with holes will let out water and rotate faster than the one without holes.
Summary
The experiments demonstrated how action and reaction forces cause movements in a bid to conserve momentum, according to the third law of Newton. The balloon moved in the opposite direction to maintain the momentum of escaping air. In the same manner, the can be rotated to maintain the momentum of the escaping water. The hypothesis is that if a water-filled can is lifted, the one with holes will let out water and rotate faster than the one without holes. The hypothesis was correct as the data demonstrated how the water-filled can with holes rotated faster than the one without holes. The problems encountered, which might have influenced the results, are windy weather and unequal holes. The windy weather affected the observation of the balloon’s movement and the can’s rotation while the use of nails created unequal holes. To avoid these problems, the experiment should be done in an enclosed room and holes drilled uniformly. A gun firing a bullet is an example of the application of Newton’s third law in everyday life.