# with earth rotating at 1000mph, when we launch ourselves from a trampoline how are we landing back at the same spot compared to launching from a moving car

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If we jump high enough to reach a hang time of 1 second, the earth would have moved quarter mile.

Also, why haven’t we devised something that allows us to stay suspended instead of using airplanes with max speed of 500mph

In: 2

Best guess is that the air around you is moving at the same relative speed as the you when you jump off the trampoline, unlike a car where you are being pelted by wind friction.

Because you and the trampoline *and the air surrounding you both* continue to move at 1000 mph in the direction of rotation

Notice the difference with the car scenario?

Momentum is conserved. If you simply jump up on on a moving platform, you’ll still be moving side ways through the air. When you are launched from a car, what happens is a *change in momentum*, i.e. the car stops moving but your body keeps moving bat the speed the car was moving before crashing.

If your car was big enough, you could jump on a trampoline in the car and see the same effect. It is your motion relative to the medium you are in.

The air and the ground move together.

If you jump up and down inside a moving vehicle like a train or a bus you will land in more or less the same place inside the vehicle that you started from.

Even jumping up and down in the bed of a moving pickup truck will not do too much unless you go fast enough for air resistance to become a serious factor.

In theory, since the air is round and the higher you go the faster you move, you wouldn’t land back exactly where you started even with air being completely still, but that effect is minor and can be ignored at the sort of heights humans can jump.

We do have things to suspend things and people above the ground, including cranes, balloons and even geostationary sattleties.

I am not sure what else you are looking for.

You are spinning along with the Earth. The atmosphere is also spinning along with the Earth.

When you jump there is absolutely nothing to slow you down. You keep the momentum. First newton’s law.

Analogy would be a bus. If you have a bus going straight at a constant speed then it’s a stable system. You can jump, you can throw a ball up and it would land back in your hand.

But if the bus was accelerating or turning (that is also acceleration in different axis from physics point of you) then you would notice a shift.