Final answer:
The time it took for a stone to hit the floor from a height of 35m is approximately 2.67 seconds when calculated using the equations of motion under gravity. The closest answer choice is Option B) 3 seconds.
Step-by-step explanation:
To determine how much time a stone was flying until it hit the floor from a height of 35m, we need to use the formula for the time of free fall under gravity. The formula is derived from the equation of motion s = ut + 1/2at², where s is the distance, u is the initial velocity, a is the acceleration, and t is the time. Since the stone is in free fall, the initial velocity u is 0 m/s and the acceleration a is equal to the acceleration due to gravity, which is approximately 9.8 m/s².
Substituting these values into the formula, we get: 35m = 0 * t + 1/2(9.8 m/s²)t². Solving for t², we get:
t² = (2*35m)/(9.8 m/s²)
t² = 70m/9.8 m/s²
t² = 7.14s²
When we take the square root of both sides to solve for t, we obtain:
t ≈ 2.67 seconds
Thus, the closest answer to the actual calculated time is Option B) 3 seconds.