Bottle Car Paper
Sean Lewis
Period 2
Sir Isaac Newton was an English physicist born 1643 in Lincolnshire. He was a genius in
many other areas also. He made quantum leaps in the scientific field in a very short period of
time. Newton’s laws improved on Aristotle’s laws which were far from perfect. Newton’s were
formulated to be universal. For example: Newton’s second law (see below) applies to both a
falling planet and a falling shoe. Without him Physics as we know it today would be nonexistent. The following are his three laws and how they apply to the Bottle Car.
Newton’s first law states that an object in motion or at rest will remain in that state
unless acted upon by a foreign unbalanced force. The car, prior to starting, will be at rest. It will
remain at rest until the car is pushed or the car is pushed through thrust in the bottle. When
the car is at motion it will remain in motion until disturbed by either an object in its linear path,
or friction acting upon the wheels and ground, the air and the whole car, and the friction acting
against the guideline and the hook.
Newton’s second law states that applied force equals mass times acceleration or F = ma.
Force is measured in newtons, which is the force to accelerate a kilogram to 1 m/s2. The applied
force is in a specific direction, just like acceleration, which makes them vectors. Whichever
direction a bottle car is pointed is the same direction that the force will cause the acceleration
to go. When the car is at rest (before launch) F = 0, while it’s mass is constant, assuming 1
kilogram, the acceleration is 0, there for 0 times 1 equals 0. During the launch, assuming the
pressure of the bottle is outputting 2 newtons, 2=1*a, to 2/1=a, the acceleration is 2 m/s 2.
When the bottle runs out of thrust, applied force is 0, so 0=1*0 again . However, this time its
Bottle Car Paper
Sean Lewis
Period 2
velocity is now higher than it was before due to the applied force. Since F= m*a, higher mass
means you need higher acceleration to equate the same applied force as opposed to an object
with a smaller mass. This is why a heavier car would not be very advantageous. Utilizing mass is
essential because the soda bottle is limited in its applied force output. If the mass is too little,
the car will be liable to spin around the wire and will have trouble staying on the ground. If the
mass is too great, the car will not move well and will have trouble getting off the starting line.
Finding the median between these two extremes will be completely beneficial to winning the
fantastic Bottle car competition.
Newton’s third law states “For every action there is an equal and opposite reaction.”
This means that when an object is moved that movement incurs an equal yet perfectly opposite
reaction. When the car is launched, the car is propelled forward and the fuel is propelled
backward. When the car is speeding through the air, the air molecules are dragged over and
behind it and rush out in the other direction. When the car hits the wall the energy from the car
meets the stiff and rigid wall half way then rebounds back into the car and runs slightly jars the
tightly packed molecules in the wall. Had this wall been made out of Jell-o, the car would’ve
bounced back less and the wall, now made of Jell-o, would’ve visibly moved exactly opposite
the car.
An equation of this car would be as follows: A car with a mass of 2 kg applied 2 newtons
of force would have an acceleration of 2 m/s2. This car starts with an initial velocity of 0 m/s2,
Bottle Car Paper
Sean Lewis
Period 2
so in 5 seconds the car will have gone 6.25 meters. Its average velocity would then be
6.25/5=1.25 m/s2. This would work in a vacuum, but not in Earth’s atmosphere. The friction of
the molecules in the air and the wheels on the ground will cause some deformities in the
answer to the equation.