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Hold on to your hats, guys and gals, this is one fast trip!
What makes a roller coaster so fun?
Some think it is the free fall
Others the speed and acceleration
Maybe it’s the fear you feel when the roller coasterSloooowly climbs that first hill!
Roller CoastersWhat keeps you in your seat on a loop?
What force powers Roller coasters?
Why do you experience free fall?
Why do you experience crushing feelings?
Where?
Where?
Inertia
Inertia
Gravity
Inertia
At the top of a hill as the train starts to go down
At the bottom of a hill as the train starts to go up
EnergyMechanical Energy
1. Potential Energy2. Kinetic Energy
Thermal Energy
1. Friction
Looping Coaster at CanobiePE = mgh
Why is this hill lower?
How can we calculate the energy lost to friction?
KE = ½ mv2
Spiral Twists
Why have these loops?
Acceleration = change in velocity over time
Velocity = speed and direction
Water Rides—are they roller coasters?Compare
Both have hillsBoth use gravityBoth have energy transformations
ContrastWater powers the ride—not gravity aloneWater is also the friction to slow down—not brakesNo trackPE to KE transformation not as key as water speed
The Boston Tea Party
The friction with the water and the blunt
shape of the car makes the wave so huge and beautiful!I love
physics
Teacher’s pet
Circular Rides—A huge varietyThis type of ride makes many people
Feel ill. How?
What do the forces look like on a swing ride?
Direction of the ride
Riders move out from the center
And in a circular pattern with constantly changing direction
This is different from a ride with a track, because there no track/seat to push back.
What is the reaction force then?
But they all work the same way
If you are going on the ride with Hagrid (a giant), should you or he sit on the outside?
What other force is at work here?Hint: it pulls you down
Hint: Which way are you being pulled or pushed?
Let’s Look at the ForcesCentripetal force
Direction of ride
C
The direction is constantly changing which means
The acceleration is constant
How does inertia figure into this?
Is this one different?Do you really need the restraints?
If someone were to say, upchuck, what direction Would the substance go?
Eww—GROSS!!!
Circular Motion
(One complete cycle)
Circular Motion
Circular Motion
Pirate Ship—Pendulum Rides
What is the thrill of this ride? What produces that thrill?
FREE FALL
Inertia
Free Body Diagram
Direction of movement
Force of Weight
The force of friction goes againstThe direction of motion
Inertia keeps the body going upWhen the ship is going back down
How Could We Calculate the Amount of Energy “Lost” Due to
Friction?Where we release the “ship”
PE = mgh
Where the highest point is after an amount of time
PE = mgh
If we find both PEs and subtract. . . h – h. . .we have it!
Now, what if we want to find the average PE lost on each swing?
Pendulum Physics
• Figure 13.4: The Simple Pendulum
Force the rider feels is defined by:
Fr = - (m)(g)(sin )
Pendulum Physics
• One Period (T):
l = length of stringg = 9.8 m/s/s
Pendulum Physics
• The frequency of oscillation is the inverse of the period:
• frequency =