Kinetic Energy Examples – Including You!

July 19, 2021
EngineeringClicks

Kinetic energy is found everywhere on Earth
It is the combination of mass and velocity
Wind mills, running, and roller coasters are just some examples of kinetic energy

Kinetic energy examples are all around us. Kinetic energy can be explained as the energy that is in all moving objects on Earth. Simply put, kinetic energy is the type of energy behind motion. It can be further defined into different types based on the various types of motion in an object.

Vibrational kinetic energy is the specific type of energy that an object has because of vibration, for example a cell phone that is vibrating possesses vibrational kinetic energy.

Rotational kinetic energy is in objects that are in a circular motion, e.g. the planets within the solar system that circle the sun possess rotational kinetic energy.

Translational kinetic energy is in objects that are moving from a particular place to another, i.e. a car driving along a road, this is probably one of the easiest examples of kinetic energy observed in everyone’s life.

Kinetic energy is dependent on two things, velocity (v) and mass (m), and is represented by the following formula:

Ek = 1/2mv2

m = Mass of the object

v = velocity of the object

Ek = Kinetic energy of the object

From the previously stated formula, it can be said that kinetic energy is directly proportional to the square of the velocity and the mass of the object that is in motion. Keeping the theoretical side of things in mind, let’s go through a couple of real-life examples of kinetic energy.

Hydropower Plants

For those who don’t know, electricity is generated by water within hydroelectric plants. Water moves through the plant, with some kinetic energy, comes into contact with the dam turbine and through this contact the water’s kinetic energy gets converted to mechanical energy of the turbine. The turbine then moves as a result of this mechanical energy, therefore producing a renewable source of electricity.

Wind Mills

One of the easiest to understand kinetic energy examples is wind mills. A windmill works when air that is in motion (and therefore possesses kinetic energy) comes into contact with the blades of the mill, converts kinetic energy into mechanical energy similar to the hydroelectric plant, and causes a rotation of the blades. This again gives way to the generation of electricity and is a renewable source of energy which is very important in the modern world. This is why kinetic energy is so important in our everyday lives!

Moving Vehicles

Cars that are moving must have some amount of kinetic energy. Cars have velocity and mass, and therefore must have some kinetic energy. If we go back to the theoretical formula of kinetic energy, we will realize that the bigger the vehicle, i.e. the more mass the vehicle has, the more kinetic energy it will have, if traveling at the same velocity. This is because the mass is again directly proportional to kinetic energy of any moving object, including cars, trucks, vans etc.

Bullets Shot From Guns

As you might imagine, a bullet exiting a gun will have extremely high kinetic energy, as it is travelling at a very high velocity. Because of this and its overall shape, it can easily go through any object it comes up against. This is largely due to the high velocity of the bullet, and not the shape. The bullet’s mass is relatively low, but its velocity still carries a significant level of kinetic energy.

Airplanes Flying

Airplanes flying in the sky possess a high level of kinetic energy as airplanes do not only have an extremely large amount of mass (about 40,000lbs!) but also has very high velocity, as airplanes regularly travel at over 500 miles per hour (MPH). Both of these factors result in airplanes in flight possessing a heightened amount of kinetic energy. An interesting fact is that kinetic energy is actually part of the physics as to why airplanes are able to fly in the first place!

Running and Walking

One of the non-obvious kinetic energy examples is walking. While we are walking to work, or out for our 6am morning run (yeah right!) we do possess some kinetic energy. The warm feeling that you experience after a strenuous walk or run is a direct result of kinetic energy. Sweat is produced by our bodies because of this exercise. Without giving too much into the biological side of things, there is a transfer of chemical energy to kinetic energy when we (eventually) get up off of the couch for a walk or run.

Cycling

Bicycles moving (with cyclists on them of course) also have some kinetic energy. I am sure you are catching the drift here as these examples are quite similar. Nevertheless, as a cyclist pedals, their body’s energy is converted into mechanical energy, which becomes potential energy and finally kinetic energy when it results in the bicycle’s wheels starting to move forward. Where more velocity is created here, more kinetic energy will follow. For the bicycle to be stopped, the brakes must be applied opposite to the force, this will then slow down the bike and bring it back to zero kinetic energy.

Roller Coasters

Now, to one of the funnest kinetic energy examples – rollercoaster! Thrill seekers love rollercoasters, but have you ever thought about the amount of kinetic energy the ride has while you are in free fall from 100 feet? Probably not. When the wagon reaches the top of its clim, it essentially has zero kinetic energy as it is stopped at the top, and then starts crawling over the “hump” which inevitably leads to the steep decline after. As it gathers speed while free falling, the increase in speed brings with it an increase in kinetic energy. The more people that are in the wagon, the greater the mass, and therefore the higher the kinetic energy, assuming that the speed remains the same throughout the ride.

Rollercoaster Funfair GIF from Rollercoaster GIFs

So, have you had any interesting experiences with kinetic energy in the past? Or do you work in a field that utilizes kinetic energy everyday for their work? We would love to hear your stories and thoughts in the comments below!