It has to do with gravitational pull.
Gravity adds a force (kgs) going downhill = sin (incline angle) * mass vehicle (kgs) and detracts the force when going uphill (same equation)
Gears are a way of trading power for speed, so that you can keep spinning at a comfortable rate regardless if you are heading up hill, staying on the flat or going downhill under power.
shift up...
No, the ski format is used with skins to climb up mountains, not for going downhill. You go downhill in board format. Then back up again in skins with ski format.
You will lose the engine braking effect, and you will also pick up speed
The energy associated with a bicycle changes as it speeds up going downhill due to the fact that potential energy is converted to kinetic energy. The potential energy is the energy of the position. The kinetic energy is the energy of movement.
Gears are a way of trading power for speed, or the other way around. They let you keep turning the pedals at a comfortable rate/resistance regardless if you are heading up hill, staying on the flat or going downhill under power.
There is no such event as "speed skiing" but Downhill skiing is basically the equivalent. In downhill racers go through a set of gates which are spaced about 100 meters apart. The objective is to get down the mountain as fast as possible. The racers usually go up to 150mph down the hill.
If you're going to do drugs, you can expect your body to react negatively to them. You're not going to speed anything up.
Up to about 10 MPH, if fully charged. Because of gravity, the momentum you create lets you go faster, given you are going downhill. Uphill the highest speed the motor will go is 10 mph, and that is only if it is fully charged.
Generally when we are going up hill because of the gravity pull, more power is needed. So when traveling uphill more power is needed than downhill.