How fast has the world's fastest car travelled? The wheel driven
record is 756Km per hour (470 miles per hour). That's the fastest
you're going to go in a regular car.
Could it go any faster? That's exactly what the Bloodhound team
have been trying to do: get a car up to speeds of 1609Km (1000
miles per hour).
How do you go faster?
The best way is to add a jet and use the air surrounding the
car. Adding a jet will give you that extra thrust you need to gain
speed. The jet does this by sucking in the air from the front of
the car and pushes it out if the back of the jet.
With just air?
Kind of, but jets don't just push still air; this would be far
too awkward! Ever heard of Newton's Third Law? It's a big
part of how jets work. Air is pushed out of the back of the jet,
but this is done at such a massive speed that it recoils and takes
the car with.
How strong is a jet engine?
The answer to this is, as you might have already guessed,
incredibly strong. A regular jet can release as much as over a
tonne of air per second, and that's one great, big push! But it's
still not enough to get the car up to 756Km per hour (470 miles per
hour). To do that you'd need an extra thrust by attaching a rocket
motor.
Rocket motors work like jets, but instead of using air they use
oxygen. It's more like a controlled explosion. To keep it on track
and moving in one direction you need to pull a neat trick. The rate
of burning must be controlled so that the high explosive in the
motor is burning at the right rate to keep the gas wall moving in
one direction. But it's not an easy feat, even experts get it
wrong.
So with a jet and a rocket engine the Bloodhound team should
have enough power to be able to get up to 756Km per hour (470 miles
per hour) in about 15 miles!
Trying it out!
To be able to move at such high speeds you need some really
long, flat runways. Back in the day beaches were used, some in the
UK, like Pendine Sands in Wales. Others were in America like
Daytona Beach or the Bonneville Salt Flats in Utah. But these too
weren't ideal because they were too short or too hard. The best
place found in recent years is somewhere called Hakskeen in South
Africa where the surface is very fine and dry mud.
Follow the bloodhound
team online!