From a point 100 m above the ground, a ball is thrown horizontally with a speed of 20 m/s . Determine the time it takes to reach the ground in seconds.

Step-by-step solution

The initial vertical velocity of the ball is u_y = 0 . The vertical displacement is s_y = 100 m . Using the second equation of motion for the vertical direction: s_y = u_y t + 1 2 g t^2 Substituting the given values and taking g = 9.8 m/s ^2 : 100 = 0 + 1 2 9.8 t^2 100 = 4.9 t^2 t^2 = 100 4.9 = 1000 49 t = 10 10 7 4.5 s