Take it to a dealer and have them check the cv joints. This could be a possibility on an older model car.
it would most likely be the bearings but in some cases sometimes the axle make a humming noise when traveling at high speeds.(front wheel drive)
tornados
it would depend on what kind of humming sound you are referring too. If you are over due on a transmission service or what not it will humm at higher speeds and as you slow down the humming slows with it, or if your brakes have gone bad it will make a humming sound once you hit over 30 mph. it could be a lot of things but those are some options to check out
if it is bearings you should hear it all the time expecially at higher speeds. Unless the sound of your engine is drowning it out. I replaced the wheel bearings on my car and it was quite simple. Plan on going to a hardware store to find socket big enough to remove your hub retainer nut.
light or soundtime
could very possibly be a broken belt in tire.
Engine rough book
The variable intake controls the amount of air pushed through the engine in order to keep it from stalling. The laws of physics that describe Air flow at speeds below Mach 1 (speed of sound) are different for air flow at supersonic speeds. So the size and shape of the engine inlet at low speeds are different that at high speeds.
At highway speeds, YES!
If you mean how do you convert , say a 500 engine to horsepower - you can't. Hp is a measure of power that the vehicle can produce, whereas 500 is the inches of the cylinders - which is a measure of the size of the engine. Although the size of the engine affects the Hp it can produce, so does the size of the vehicle (it's weight), and the speed it's running (Hp is always given at a certain RPM, as the engine's efficency is different at different speeds). Hope that helps. PS you can convert the Cu In to Litres, like 1 liter is about 61 cubic inches.
The speed of sound depends on what the sound is going through, not on what created the sound. If sounds from different sources had different speeds, then there could never be a band, orchestra, or choir.
Probably a matter of where the engine's power band is set out, or you may simply be bogging the engine down at lower speeds. Try downshifting and keeping your RPMs up a little.