The time it takes for an object to reach a certain level given the distance and the initial velocity can be calculated through the equation,
d = V₀t + 0.5gt²
Where d is the distance, V₀ is the initial velocity, g is the acceleration due to gravity and t is time. Substituting the known values from the given above,
25 = (-7.5)(t) + 0.5(9.8 m/s²)(t²)
The value of t from the equation 3.15s. Hence, it will take the object 3.15 seconds to reach the ground.
