## Neglecting the effect of air resistance how long a stones takes to dropped off a 125m high building stand’s on the ground, take g = 10m/s2?

A. 3 Sec

B. 4 Sec

C. 18 Sec

D. 5 Sec

### Answer

Correct Answer: **D. 5 Sec**

### Detail about MCQs

When neglecting the effect of air resistance, you can use the following kinematic equation to calculate the time it takes for a stone to fall from a certain height:

Distance=12×Acceleration×Time2Distance=21×Acceleration×Time2

In this case, the distance is 125 meters (height of the building), and the acceleration due to gravity (g) is given as 10 m/s^2. We need to find the time (t). Rearrange the equation to solve for time:

125 m=12×10 m/s2×Time2125m=21×10m/s2×Time2

Now, solve for Time:

Time2=2×125 m10 m/s2=25 s2Time2=10m/s22×125m=25s2

Taking the square root of both sides:

Time=25 s2=5 sTime=25s2=5s