To solve this problem, we can use the equation of motion for uniformly accelerated motion:
v = u + at
Where: v = final velocity u = initial velocity a = acceleration t = time
In this case, the ball is thrown downwards, so the acceleration due to gravity, g, is acting in the same direction as the motion. Therefore, the acceleration is -g.
Given: Initial velocity, u = 20.0 m/s (downwards) Final velocity, v = 50 m/s (downwards) Acceleration, a = -g = -9.8 m/s² (downwards)
Using the equation of motion: v = u + at
50 = 20 + (-9.8)t
Simplifying the equation: 50 - 20 = -9.8t 30 = -9.8t
Dividing both sides by -9.8: t = 30 / -9.8 t ≈ -3.06 seconds
The negative value for time indicates that the ball reached the final velocity in the opposite direction (upwards) before being thrown downwards. Since time cannot be negative in this context, it is likely that there is an error or misunderstanding in the problem statement. Please double-check the given information.