a 1kg rock is thrown down a building 100m high. how long does it take for the rock to reach the ground?
To find the time it takes for the rock to reach the ground, you can use the kinematic equation for free fall:
𝑑 = (1/2)𝑔𝑡^2
In this equation, 𝑑 represents the height of the building (100m), 𝑔 is the acceleration due to gravity (approximately 9.8 m/s^2), and 𝑡 represents the time it takes for the rock to reach the ground.
Rearranging the equation to solve for 𝑡, we have:
𝑡^2 = (2𝑑)/𝑔
Plugging in the values, we get:
𝑡^2 = (2 * 100) / 9.8
𝑡^2 = 20.408
Taking the square root of both sides, we find:
𝑡 = √20.408
𝑡 ≈ 4.52 seconds
Therefore, it takes approximately 4.52 seconds for the 1kg rock to reach the ground.