The two aspects of physics, which I will talk on, are potential and kinetic energy and momentum.
Gravitational Potential energy and kinetic energy
GRAVITATIONAL POTENTIAL ENERGY
Gravitational potential energy is energy gained as a result of position of a body on which forces act. The force, which acts on the body, is gravity, which pulls it down. When the object is lifted, work is done to move it against gravity. This is what makes the object gain gravitational potential energy, which it uses to do work when it is brought down.
G.P.E = mass x g x vertical displacement moved
KINETIC ENERGY
Energy is needed to get a body moving but while it is moving the body now gains energy of its own which can be used to do work. This is known as kinetic energy.
K.E = ½ x mass x (velocity)
Conservation of energy
This states that energy is neither created nor destroyed. When forms of energy are changing, the conversion is not always 100% but because of the law of conversion of energy we cannot say the energy has been destroyed, we can only say that it has been changed to a form, which was lost to the surrounding. For example energy but into a bulb (electrical energy) is not the same given out, some of the energy is given off as heat.
The application of the concept at chessington was with the ride called vampire, which is explained below
VAMPIRE
This is a track ride, which can be called a roller coaster. It was made by arrow dynamics in Utah USA, from 1989-1990. It has three trains with seven carriages per train and four riders per carriage.
The working of the vampire apart from the help of gravity is based on the interconversion of potential energy to kinetic energy and vice versa at various stages of the ride. Like the free fall ride the train is taken up the first hill. The purpose of this initial ascent is to build up a sort of reservoir of potential energy. The concept of potential energy, often referred to as energy of position, is very simple: As the coaster gets higher in the air, there is greater distance gravity can pull it down. The potential energy the train builds going up the hill can be released as kinetic energy, energy of motion, as soon as it starts coasting down the hill. The diagram below shows how this works.
A roller coaster's energy is constantly changing between potential and kinetic energy. At the top of the first lift hill (a), there is maximum potential energy because the train is as high as it gets. As the train starts down the hill, this potential energy is converted into kinetic energy -- the train speeds up. At the bottom of the hill (b), there is maximum kinetic energy and little potential energy. The kinetic energy propels the train up the second hill (c), building up the potential-energy level. As the train enters the loop-the-loop (d), it has a lot of kinetic energy and not much potential energy. The potential-energy level builds as the train speeds to the top of the loop (e), but it is soon converted back to kinetic energy as the train leaves the loop (f).
Since an object in motion tends to stay in motion (Newton's first law of motion), the train will maintain a forward velocity even when it is moving up the track, opposite the force of gravity. When the coaster ascends one of the smaller hills that follows the initial lift hill, its kinetic energy changes back to potential energy. In this way, the course of the track is constantly converting energy from kinetic to potential and back again. This fluctuation in acceleration is what makes roller coasters so much fun.
CALCULATING THE HEIGHT OF THE RIDE
To calculate the height of the ride we have to derive a formula using the formula for potential and kinetic energy.
P.E = K.E
Using that g =9.81, V =
We all know that in theory we say all the potential energy changes to kinetic energy, but in practise this is not so energy is lost to friction between the train and the track, the train and the air and sound. So this makes the velocity which can be calculated not to be the same as the actual velocity.
MOMENTUM
Momentum is the product of mass and velocity. It allows you to do calculations about what happens when moving bodies collide. Momentum is a vector quantity whose direction is the same as that of the velocity of the body.
When two bodies collide, there is a change in momentum of each body. The change in momentum is the difference between the final and initial momentum. When change in momentum is negative, when right is positive it means that the change in momentum is to the left.
In a collision, momentum is always conserved. This is stated in the law of conservation of momentum, which says that if there are no external forces acting on a number of bodies, momentum is conserved. This means the total momentum before collision is equal to the total momentum after collision.
There are two types of collision- elastic and inelastic collision.
Elastic collision- This is collision in which kinetic energy and momentum are conserved. E.g the collision of molecules of gas in a container.
Inelastic collision- this is collision in which momentum is conserved but kinetic energy is not conserved. E.g. Collision between two cars.
TINY TRUCKERS
This ride is basically bumper cars with a different name. We all know this ride where we enter cars and start bumping into each other. This ride operates using Newton’s third law of motion. This law states that if a body exerts a force on a second body, the second body exerts an equal but oppositely directed force on the first body.
The bumper cars are designed to collide without danger to riders. Each car has a large bumper, which is made of rubber round it. This rubber bumper prolongs the impact and diffuses the force of collision. The cars run on electricity, which is carried by a pole on the back of the car that leads up to, a wire grid in the ride’s ceiling. The grid carries electricity that runs the car. The electrical energy carried to the car from the grid is converted to kinetic energy.
When the bumper cars collide the drivers feel a change in motion and also feel their inertia. When this happens the direction of the car change but the riders continue to move in a straight line and so it is important that seat belts are worn.
The masses of the drivers affect collision also. A difference in masses between two drivers means that one driver experiences more change in motion than the other.
Another principle, which comes into play in bumper cars, is Momentum. Momentum is the product of mass and velocity. A bumper car, which is moving, has momentum. When two bumper cars collide the total momentum before and after collision remains the same.
The electrical energy is not all converted to kinetic energy because some of it is converted to heat.
Examples involving bumper cars
If a bumper car with a woman of 50kg is stationary and is hit by another bumper car with a 90kg man. Predict the direction the cars will move and the final velocity after collision if the moving bumper car has a velocity of 20m/s.
Answer: The two bumper cars will move in the direction of the bumper car with the 90kg man.
For the calculation:
Momentum before collision = Momentum after collision
Bibliography: I used the and appreciated the following websites:
ONONUJU OKONKWO
ST TERESA’S SCHOOL
