Answer:
<em>Choice: c. 6sec</em>
Explanation:
<u>Horizontal Launch </u>
When an object is thrown horizontally with a speed (v) from a height (h), it describes a curved path ruled by gravity until it finally hits the ground.
The horizontal component of the velocity is always constant because no acceleration exists in that direction, thus:
The vertical component of the velocity changes in time because gravity makes the object fall at increasing speed given by:
Where
To calculate the time the object takes to hit the ground, we use the same formula as for free-fall, since the time does not depend on the initial speed:
The marble rolls the edge of the table at a height of h=180 m, thus:
t = 6 sec
Choice: c. 6sec