Acceleration: refers to a change in speed or direction of travel. Any change will produce acceleration, but tremendous speed in a straight line will not. It’s only when you change the direction or increase the speed that the pressure of acceleration is felt. When speed is decreased, it is felt again, but this time it is called deceleration.
Acceleration:decelerationAirlock: entering or leaving a spaceship in deep space, you can’t simply walk through a door, for there is neither air nor pressure outside, and both air and pressure would escape from the ship if you did. Instead, you use an airlock, a device consisting of two doors with a small tunnel in between. Upon leaving the ship, the inner door is shut before the outer one is opened, and the reverse is true upon entering. That way, air
