Because we don't want to die.
Yes - falling out of an airplane. Use a parachute.
Press A while falling.
There's no air
Kangaroos and other macropods such as wallabies and wallaroos use their tail to balance while jumping.
While there had previously been designs of parachutes and failed attempts to use them, the first functional parachute was invented and demonstrated by Sebastian Lenormand in 1783.
ham string
you can use this thing called a parachute to get your speed up.
Indeed why? There are videos of examples where a parachutist has deliberately set fire to their parachute in flight, however this is part of a stunt. For 99.9999999% of skydivers, they do not set fire to their parachute as it is needed to save their life. For your information, all skydivers wear a reserve parachute for use in the case of a malfunction of the main parachute.
A iPhone can be used on a airplane. You will not be able to call or use the internet.
Acceleration due to gravity is the same ONLY if you assume there is no air resistance. This is definitely not the case if you use a parachute.
No. Even if a laptop has internet, it does not work while flying on an airplane, because there is no Wi-Fi on an airplane, or in the sky.
Yes. Often passengers will use the lavatories while others are taking their seats.