Answer: 
Explanation: The time taken by the object to reach the ground depends up on the vertical velocity of the object.
The object horizontal velocity component only moves the object in forward direction and does not have any effect vertically
as the object is launched horizontally its initial vertical velocity is zero
the object experiences downward fall due to gravitational acceleration only since there is no air resistance
therefore a=g
the distance covered =s=h
now the kinematic equation could be used
Below the crust is the mantle, a dense, hot layer of semi-solid rock approximately 2,900 km thick. The mantle, which contains more iron, magnesium, and calcium than the crust, is hotter and denser because temperature and pressure inside the Earth increase with depth.
Hope this helped! :)
Can I be brainliest please?
To solve this problem it is necessary to apply the concepts of Work. Work is understood as the force applied to travel a determined distance, in this case the height. The force in turn can be expressed by Newton's second law as the ratio between mass and gravity, as well
Where,
m = mass
h = height
g = Gravitational constant
When it ascends to the second floor it has traveled the energy necessary to climb a height, under this logic, until the 4 floor has traveled 3 times the height h of each of the floors therefore
Replacing in our equation we have to
The correct answer is 4.
