<em>IF</em> this is happening on <u>Earth</u>, then the acceleration of gravity wherever the captain and the roof are is about 9.8 m/s² downward.
<em>IF</em> his shield is not affected by air resistance, and it's free to behave under the influence of gravity alone, then its acceleration is <em>9.8 m/s² downward</em>, from the moment it leaves his hand until the moment it hits a building, a tree, a car, a bus, an evildoer, or the ground.
Whatever speed it has when it leaves his hand, in whatever direction, makes no difference.
Gravity i think but if uts not gravity then it will be air resistance
<span>The electric force between two charged objects depends on
the product of their charges and the distance between them.</span>
John Dalton. Modern Atomic Theory (John Dalton) Experiments with gases that first became possible at the turn of the nineteenth century led John Dalton in 1803 to propose a modern theory of the atom based on the following assumptions. 1. Matter is made up of atoms that are indivisible and indestructible.
