Newton and the Laws of Motion and Bumper Cars
Most people know Sir Isaac Newton for his discovery of gravity, which is thought to have
been triggered when he watched an apple drop from a tree. But Newton was also
responsible for laying down the fundamental laws of the physical universe: the principles
that describe not only how things work but why. These principles are his laws of motion,
and they built on the work of great scientific minds who came before him.
Newton was born in Lincolnshire, England, in 1642, only a few years after the death of
Galileo Galilei. He showed no particular talent for farming (his family's line of work), but a
true genius for mathematics. Building on the work of predecessors such as Galileo,
Copernicus, and Kepler, he laid out the principles of his laws of motion, the universal
theories that tied the work of these great minds together. He once confessed, "If I have
seen further than other men, it is because I stood on the shoulders of giants."
Newton was insecure, bad tempered, and sometimes reclusive--not exactly the friendly
figure of folklore who was charmed by the fall of an apple. But he explained the physical
laws that allow us to walk on the moon and build ever more exciting amusement parks.
These are the laws of motion he laid down:
The First Law of Motion: The Law of Inertia
Newton's first law expanded on the work of Galileo. This well-known law states that bodies
in motion tend to stay in motion, unless they are acted on by an external force. Also,
bodies at rest tend to stay at rest, unless they are acted upon by an external force.
This law governs why a driver is thrown forward in a head-on automobile accident. The
car may have stopped, but the driver continues moving forward unless held in place by a
seatbelt.
The Second Law of Motion: The Law of Acceleration
Newton's second law explains how the mass of an object and the amount of force applied
to an object are related to acceleration. In brief, it says that the greater the mass of an
object, the more it resists being moved and therefore the smaller its acceleration will be. It
also says that the greater the force applied to an object, the greater the object's
acceleration will be.
To understand this law, imagine pushing a pebble, and then imagine pushing a boulder.
The pebble has a smaller mass, and so will accelerate faster than the boulder will. Now
imagine pushing a boulder with your bare hands and then imagine pushing it with a
powerful backhoe. The backhoe is able to exert more force on the boulder, and so will
make it accelerate faster than when you pushed it with your bare hands.
The Third Law of Motion: The Law of Interaction
Newton's third law explains how objects interact with other objects. It's based on the idea
that every action produces an equal and opposite reaction. But what does this really mean?
Think about the bumper cars. When you hit another car, you exert a force on that car.
That's not the end of it, though. Even if you hit a car that is at rest, that car is also exerting
a force on you. These forces are opposite, or moving in different directions from each
other.
Here's another example. When you jump up in the air, you must first propel yourself by
pushing away from the earth (or in other words, pushing the earth away). You can't
perceive it, but the earth responds by pushing you away from it. Both your push against
the earth and the earth's equal and opposite push against you propel you into the air.
Bumper Cars
Newton's third law of motion comes into play on the bumper cars. This law, the law of
interaction, says that if one body exerts a force on a second body, the second body exerts
a force equal in magnitude and opposite in direction on the first body. It's the law of actionreaction, and it helps to explain why you feel a jolt when you collide with another bumper
car.
How do bumper cars work?
Bumper car rides are designed so that the cars can collide without much danger to the
riders. Each car has a large rubber bumper all around it, which prolongs the impact and
diffuses the force of the collision.
The bumper cars run on electricity, carried by a pole on the back of the car that leads up
to a wire grid in the ride's ceiling. This grid carries the electricity that runs the car.
Electrical energy carried to the cars from the grid is converted to kinetic energy, some of
which is converted to heat.
What happens to the drivers?
When bumper cars collide, the drivers feel a change in their motion and become aware of
their inertia. Though the cars themselves may stop or change direction, the drivers
continue in the direction they were moving before the collision. This is why it's important to
wear a seat belt while driving a real car, since otherwise you could suffer injury being
thrown forward in a collision.
The masses of the drivers also affect the collisions. A difference in mass between two
bumper car riders will mean that one rider experiences more change in motion than the
other (or more of a jolt). The type of collision, velocity of the cars, and mass of the
individual drivers all come into play in bumper car collisions.
Write a 5-7 paragraph 500 word essay that describes how
Newton’s Laws work with Bumper Cars.