Since the ball is projected horizontally, its initial vertical velocity is zero. We can treat the motion in the horizontal direction and vertical direction independently.
Given: Initial horizontal velocity (u_x) = 40 m/s (constant) Time (t) = 3 seconds
Since there is no air resistance, the horizontal velocity remains constant throughout the motion. Therefore, the horizontal speed of the ball after 3 seconds will still be 40 m/s.
In the vertical direction, the ball experiences the acceleration due to gravity, which is approximately 9.8 m/s² (assuming no air resistance).
Using the equation for vertical motion:
v_y = u_y + a * t
Since the initial vertical velocity (u_y) is zero, the equation simplifies to:
v_y = a * t
Substituting the values:
v_y = 9.8 m/s² * 3 s v_y = 29.4 m/s
Therefore, after 3 seconds, the vertical speed of the ball will be 29.4 m/s. However, since the ball was projected horizontally, the vertical speed does not affect the horizontal speed of 40 m/s.