# A Flying Tesla? Sure! We Calculate the Power Demands

WIRED | 1/12/2019 | Rhett Allain
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Click For Photo: https://media.wired.com/photos/5c391f014feec32ca0f58fc0/191:100/pass/tesla-491956850.jpg

Elon Musk isn't afraid to play around on Twitter. In a recent tweet, Musk suggested that a future Tesla would look like the flying car from Back to the Future.

Ha ha. Funny. But could it really work? What would it take to make a flying Tesla that converts from driving to flying mode with the thrust coming out of the wheels? Time for some physics.

#### Couple - Options - Telsa - Ground - Method

I can think of a couple options for getting a flying Telsa off the ground. The first method would be rocket propulsion. This seems to be what Elon wants to use (a natural choice because of the connection with SpaceX). In fact, it appears he's not even joking.

I'm not a rocket expert, but it seems like you would have to keep refueling the rockets. It would be a nice stunt, but not for everyday use.

#### Way - Car - Type - Air - Thruster

However, there is another way to make a car fly—some type of air thruster. It doesn't matter if you use some type of jet engine or a rotor, the physics is mostly the same. In order to hover, the flying car will take air from above the car and "throw" it down. Since air has mass, a change in velocity of this air would mean it has a change in momentum (where momentum is the product of mass and velocity). According to the momentum principle, this change in momentum requires a force—and it is this force that counteracts the gravitational force to make the car fly.

Of course, you can't hover for free. Throwing this air down to produce lift requires energy. In order to hover, you need to keep using energy every second. The energy goes into the kinetic energy of the air which depends on both the mass and the velocity of the air. Since the car continues to throw air...