Presentation on theme: "Hold on to your hats, guys and gals, this is one fast trip!"— Presentation transcript:
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 its the fear you feel when the roller coaster Sloooowly climbs that first hill!
Roller Coasters What 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? 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
Energy Mechanical Energy 1. Potential Energy 2. Kinetic Energy Thermal Energy 1. Friction
Looping Coaster at Canobie PE = mgh Why is this hill lower? How can we calculate the energy lost to friction? KE = ½ mv 2
Spiral Twists Why have these loops? Acceleration = change in velocity over time Velocity = speed and direction
Water Ridesare they roller coasters? Compare Both have hills Both use gravity Both have energy transformations Contrast Water powers the ridenot gravity alone Water is also the friction to slow downnot brakes No track PE 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 Teachers pet
Circular RidesA huge variety This 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?
Lets Look at the Forces Centripetal 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? EwwGROSS!!!
Circular Motion (One complete cycle)
Pirate ShipPendulum 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 against The direction of motion Inertia keeps the body going up When 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?
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 string g = 9.8 m/s/s
Pendulum Physics The frequency of oscillation is the inverse of the period: frequency =