To calculate the time of a falling object with only its speed, you can use the formula t = v/g, where t is the time, v is the initial velocity (or speed) of the object, and g is the acceleration due to gravity (usually 9.8 m/s^2).
If the object is not falling in a vacuum, you will need to take into account the air resistance or drag. This will affect the acceleration of the object, and therefore the time it takes to fall. The formula for time in this case is more complex and depends on the shape and size of the object, as well as the density and viscosity of the air.
Yes, this formula can be used for objects with different masses as long as they are all falling from the same height and under the same conditions (e.g. in a vacuum). This is because the acceleration due to gravity is constant regardless of the mass of the object.
If the object has an initial velocity in addition to its falling speed, you will need to use the formula t = (v + u)/g, where u is the initial velocity and v is the final velocity (which is equal to the falling speed). This formula takes into account the initial velocity of the object and calculates the time it takes to reach the final velocity (falling speed).
No, the time it takes for an object to fall will vary depending on the height it is falling from. The formula t = v/g assumes that the object is falling from a height of 0 meters. If the object is falling from a different height, you will need to use the formula t = √(2h/g), where h is the height of the object. This formula takes into account the initial velocity of the object as well as the height it is falling from.