A projectile is launched horizontally with a speed of 80.0 m/s. If the projectiles is launched above the floor, how long does it take the projectile to hit the floor?

wouldn't it depend on how high it was initially?

I think the initially velocity is 0.

To determine how long it takes for the projectile to hit the floor, we can use the concept of time and the equation of motion. Since the projectile is launched horizontally with a constant speed, the initial vertical velocity is zero.

The equation that relates the vertical motion of the projectile is:

y = (v0y * t) + (1/2) * a * t^2

where:
- y is the vertical distance traveled by the projectile (height above the floor),
- v0y is the initial vertical velocity of the projectile (zero in this case),
- t is the time taken,
- a is the acceleration due to gravity.

We can simplify the equation since the initial vertical velocity is zero and the only acceleration acting on the projectile is the acceleration due to gravity. Therefore, the equation becomes:

y = (1/2) * a * t^2

Since y represents the distance above the floor, when the projectile hits the floor, y becomes zero. Therefore, our equation becomes:

0 = (1/2) * a * t^2

Rearranging the equation, we can solve for t:

t^2 = (2 * y) / a

Now, substitute the values into the equation:
- y = 0 (since the projectile hits the floor),
- a = 9.8 m/s^2 (acceleration due to gravity).

t^2 = (2 * 0) / 9.8
t^2 = 0

Taking the square root of both sides, we find:

t = 0

Therefore, it takes 0 seconds for the projectile to hit the floor.