Answer:
She stone hit ground 42.86 m far from base of cliff.
Explanation:
Initial height from ground = 40 meter.
We have equation of motion , , s is the displacement, u is the initial velocity, a is the acceleration and t is the time.
In this the velocity of body in vertical direction = 0 m/s, acceleration = 9.8 , we need to calculate time when s = 40 meter.
Substituting
So it will take 2.86 seconds to reach ground.
So, stone travels horizontally at 15 m/s for 2.86 seconds.
Distance travelled = 15 x 2.86 = 42.86 m
So, the stone hit ground 42.86 m far from base of cliff.