Principle of Physics 1 Potential Energy

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Principle of Physics 1Potential Energy

• At the top of the lift hill, the potential
• energy of the coaster is at its greatest-
• the coaster is at its highest elevation.
• As gravity gives the car velocity, the
• potential energy is transferred into kinetic
• energy.
• The coaster does, however, regain some
• potential energy each time it climbs
• another hill or ramp on the rest of the ride.

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Principle of Physics 2Gravitation

• powers the coaster throughout the entire
• At this point in the ride, the potential energy
  of this mechanical system begins conversion into
  kinetic energy as the coaster reaches a high rate
  of speed through acceleration.

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Principle of Physics 3Freefall

• Free-fall, or airtime
• During free-fall the car exerts no pressure on
  the riders or the track the riders feel only the
  force of gravity.
• When inertia and gravity are equal forces, rider
  may experience the condition of weightlessness.
  Or 0 gravity. But only briefly

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Principle of Physics 4Velocity

• how fast and in what direction the coaster
• is moving.
• The ride goes through many changes in
• speed and direction.
• Because of the change in velocity, the riders
• experience upward acceleration in the form of
• positive g-forces.
• The compression makes the rider feel heavier
• than normal.

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Principle of Physics 5Projectile Motion

• A projectile is an object that is thrown (like
  a baseball).
• Neglecting air resistance and spin effects, a
  projectile thrown outward into the air follows
  the path of a parabola. There is no force of
  horizontal acceleration, only a constant
  horizontal velocity. The object is in freefall.
• The riders experience the sensation of
  weightlessness as they follow the parabolic path
  of projectile motion from the point of elevation
  (top of the hill.)
• The challenge for the roller coaster designer is
  to design the track so that the shape of the hill
  follows a curved path of an object that has been
  thrown.

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Principle of Physics 6Acceleration
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Principle of Physics 7Centripetal Acceleration

• A body traveling in a circular path.
• Acceleration force is supplied by gravity and
  is directed toward the center of the circle
  (centripetal force)
• lateral G force convert to positive g-forces

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Physics Principle 11Kinetic Energy

• When work is done on the coaster (gravitational
  forces act) energy is transferred, and the
  coaster speeds up and gains Kinetic energy
• Depends on motion of the car and mass.
• Transfer of energy between PE and KE is what
  powers the coaster.

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Principle of Physics 8Friction

• Friction plays a major role in actual roller
  coaster physics, where mechanical energy (the sum
  of potential and kinetic energy) is not constant
• The friction of the wheels on the track, the
  wheel bearings in oil, and wind drag all
  contribute to energy of the car is lost. This
  reduceds velocity
• Some roller coasters successfully project the
  illusion of greater speeds at the end of a ride
  through the creation of tight curves with flat
  banks and small, fast speed bumps.

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Principle of Physics 9Acceleration Stress

• Riders of roller coasters are especially subject
  to the effects of acceleration because of the
  high-speed drops, turns, and inversions of the
  coaster.
• Acceleration forces are measured in units of
  gravitational acceleration, or g.
• One g is a force equivalent to the weight of the
  coaster on the surface of the earth.
• A force of 3 g, for example, is equivalent to an
  acceleration three times that of a body falling
  near the Earth.

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G-Forces,

• What are they?
• Weight is the pull of gravity
• 1 pd. 4.45 N
• On earth all objects (neglecting air resistance)
  will speed up at 9.8 m/s2 or 22 mph for every
  second they fall.
• Any time an obj. experience the pull to the
  force of gravity, its said to be in a 1-g
  environment
• An obj. dropped accelerates down at 9.8 m/s2, we
  say the obj. is in a 1-g environment
• 1 g 9.8m/s2 22 mph/s

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G-Force continued..

• On Earth
• 1-g environment rock weighs 100 lbs
• 2-g environment rock weighs 200 lbs
• 9-g environment rock weighs 900 lbs
• Negative Gs
• -2gs it would take 200 lbs to hold the rock
  down on the ground.
• -5gs it would take 500 lbs to hold the rock
  down to the ground.
• 0gs it would be weightless

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Principle of Physics 10Centrifugal Force

• Centrifugal force can be increased by increasing
  either (1) the speed of rotation, (2) the mass of
  the body, or (3) the radius, which is the
  distance of the body from the center of the
  curve.
• In the physics of motion, the corkscrew
  functions much the same way as a vertical loop