CBSE Class 11-science Answered

Let the distance travelled by the marble in 1 sec is x meter. Then the stone would have travelled (10-x) meter from the point 5 mt above the ground.

For the motion of marble using second equation of motion

h = u t + (1/2) g t²

x = 0 + (1/2) x 10 x 1²         (where g = 10 m/s², t = 1 sec)

x = 5 m

Now for the motion of stone, using second equation of motion

h = u t + (1/2) g t²

where u is the initial speed of the stone.

10 – x = u t + (1/2) g t²

10 – 5 = u x 1 + (1/2) x 10 x 1²

u = 10 m/s