Answer:
Choice: c. 6sec
Explanation:
Horizontal Launch
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:
[tex]v_x=v[/tex]
The vertical component of the velocity changes in time because gravity makes the object fall at increasing speed given by:
[tex]v_y=g.t[/tex]
Where [tex]g=10 m/s^2[/tex]
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:
[tex]\displaystyle t=\sqrt{\frac{2h}{g}}[/tex]
The marble rolls the edge of the table at a height of h=180 m, thus:
[tex]\displaystyle t=\sqrt{\frac{2*180}{10}}[/tex]
[tex]\displaystyle t=\sqrt{36}[/tex]
t = 6 sec
Choice: c. 6sec
