Final answer:
The time for a ball to hit the ground when thrown horizontally from a building is independent of its horizontal velocity. Therefore, even if the ball is thrown at twice the initial speed, it will still take 1.00 s to hit the ground.
Step-by-step explanation:
The subject of this question is Physics, specifically pertaining to the concept of projectile motion. The time it takes for an object dropped from a certain height to reach the ground is independent of the horizontal velocity, as the horizontal and vertical motions are independent of each other. Therefore, the correct answer to the question of how long it would take for a ball thrown horizontally from the top of a building at twice the speed to hit the ground would be (c) 1.00 s. Throwing the ball with a greater horizontal velocity does not affect the time it takes to fall, given that gravity acts only in the vertical direction and if we are ignoring air resistance.