Hovering cars vs wheeled cars

[Abheer Parashar]

TL;DR Summary

Are hovering cars actually sensible to be used ?

Hello everyone, I am Abheer and I am a high school student. I wanted to ask that in few sci-fi films I saw hovering cars and now I am wondering, are they really a better alternative than 'wheeled' cars in general (like saving energy being wasted due to friction and also being fast), or are they just good for sci-fi and will cause huge infra expenditure to set up and tough to maintain (if the MagLev concept is applied to cars, for example) ?

 

[Baluncore]

Wheels keep trains on the track. Maglev follows a rail, but without wheels. Tyres keep cars on the road. A hover car has no rails. A hover car would need some way of not sliding sideways, down the hill.

 

[Tom.G]

You might think about how hard you would have to work to hold a car in the air. If you haven't tried it, ask a parent, teacher, or neighbor to help you jack up a car to change a flat tire. When you get thru, realize that you have raised less than half the car weight.

Unfortunately that energy is not free, it has to come from SOMEWHERE... and it is a lot more than the friction losses, which are there only during movement.

Keep up the creative thinking though! That is how progress is made.

Cheers,
Tom

 

[phinds]

TL;DR Summary: Are hovering cars actually sensible to be used ?

Well, let's think about some of the difficulties/challenges:

• How do they go up and down hills?
• What happens when several of them are near each other?
• What happens when there is a light surface of water when it's raining?
• How do they act in a heavy rain?
• How do they act in strong winds?
• How do they turn corners and what effect might that have on other hovercraft around them?
• How do they stop and what effect might that have on others around them, especially if there are a line of them at a stoplight?

I could go on, but perhaps you get the point.

 

[Abheer Parashar]

You might think about how hard you would have to work to hold a car in the air. If you haven't tried it, ask a parent, teacher, or neighbor to help you jack up a car to change a flat tire. When you get thru, realize that you have raised less than half the car weight.

Unfortunately that energy is not free, it has to come from SOMEWHERE... and it is a lot more than the friction losses, which are there only during movement.

Keep up the creative thinking though! That is how progress is made.

Cheers,
Tom

It means that just to escape from the effect of friction of wheeled cars, the hovering cars are stupidity bcz they require more power ?

 

[Tom.G]

If you insist, I can go along with that. But there is no need to beat yourself up over it.

Cheers,
Tom

 

[Drakkith]

There's a reason that helicopters and other aircraft based on similar principles aren't used to transport goods except in very special cases. They just aren't efficient enough. Hovering cars run into the same issue. As a comparison, the Bell 206 JetRanger is a 4-passenger helicopter weighing 3300 lbs at max takeoff weight. This is comparable to a Toyota Camry in weight and passenger capacity. The JetRanger uses about 115 liters of fuel (30 gallons) per hour of flying and does about 115 MPH at average cruising speed. Assuming that the best fuel efficiency occurs somewhere around cruising speed, this is a fuel efficiency of about 4 mpg, less than 1/10th of a modern Toyota Camry.

Even if this back of the envelope math is off by a factor of 2x or even 3x, a helicopter comes nowhere near the fuel efficiency of a modern car. Hovering cars suffer from the same limitations in addition to being MUCH more complicated to build and operate and much more dangerous in the event of 'driver' error or equipment malfunction compared to ground cars.

 

[Rive]

Are hovering cars actually sensible to be used ?

Depends on the application
https://www.craneblogger.com/wp-content/uploads/2009/11/Lawn-mower-crane-hedge-trim.jpg
... Joke aside, I think they would be more like some kind of low-end helicopters than real cars: and that brings the special driving licence and lots of safety considerations. More bother than fun, in the foreseeable future.
But of course, if you have enough wealth to waste and wide grasslands to traverse then they would be a considerable option.

 

[anorlunda]

There are about 25 million km of highways in the world. Is there enough copper in the world to make the coils for that much maglev track?

Alternatively, what happens when a maglev car reaches the end of maglev track and needs to continue on conventional roads?

 

[bob012345]

TL;DR Summary: Are hovering cars actually sensible to be used ?

Hello everyone, I am Abheer and I am a high school student. I wanted to ask that in few sci-fi films I saw hovering cars and now I am wondering, are they really a better alternative than 'wheeled' cars in general (like saving energy being wasted due to friction and also being fast), or are they just good for sci-fi and will cause huge infra expenditure to set up and tough to maintain (if the MagLev concept is applied to cars, for example) ?

Welcome to PF!

A self powering hovering car the Avrocar has been built in the 1950's. Here is a short video. If it interests you you can look at some of the longer design videos that will be linked.



You can judge for yourself if it seems practical.

 

[gggnano]

Um yeah...it's called gravity and gravity is a big problem for flight on earth.

To the best of my knowledge the cheapest method for a single-person transit these days isn't a car but electric scooter which is even more efficient than say solar car and obviously fossil fuel cars or bikes and to give you the number an electric scooter can be 10, 15 or even 20 times more efficient than personal ultralight airplane. Example: an ultralight airplane powered by diesel fuel can burn say 2 litres of diesel per 100km which is some 76 megajoules while for 100km el. scooter can use 5 megajoules or less. Of course with an airplane you have the advantage to fly through shortcut but it's more noisy and riskier. It's also much faster.

Have a look at this fantastic explanation of how much energy would you need to deal with gravity while flying, and since you said you're highschool student just ignore the integral/parenthesis/exotic symbols and focus on the simple multiplication and division to see the real calculation:

https://www.learnthermo.com/examples/example-problem

 

[phinds]

@gggnano The OP was last seen 3 weeks ago. Looks like he left 4 days after joining, so don't expect an answer.

 

[berkeman]

To the best of my knowledge the cheapest method for a single-person transit these days isn't a car but electric scooter which is even more efficient than say solar car and obviously fossil fuel cars or bikes and to give you the number an electric scooter can be 10, 15 or even 20 times more efficient than personal ultralight airplane.

Nope.

https://www.bicycling.com/rides/a20039883/9-ways-to-make-bike-commuting-easier/

 

[bob012345]

Nope.

https://www.bicycling.com/rides/a20039883/9-ways-to-make-bike-commuting-easier/

Are you answering cheapest or most efficient or both?

 

[berkeman]

Are you answering cheapest or most efficient or both?

I bicycle for food...

 

[bob012345]

I bicycle for food...

In Dallas we actually have bike trails all around the city.

 

[Drakkith]

In Dallas we actually have bike trails all around the city.

In Shreveport we often don't even have sidewalks, let alone bike trails. I have a sidewalk in front of my house, but one of the main cross roads connected to my street does not.

 

[Tom.G]

I bicycle for food...

Sounds like a pretty low pay rate.