two rock are thrown off the edge of a cliff one is thrown horizont at a speed of 25 m s the other dropped straight down. which stone will hit the ground first? why?

in the vertical direction the motion of the two rocks is identical. They accelerate down with acceleration -9.81 m/s^2

The fact that one of them is moving with constant velocity (there is no force in the x direction) is irrelevant to the motion in the vertical direction

Therefore they hit simultaneously.

To determine which stone will hit the ground first, we need to understand the concept of projectile motion and the effect of gravity.

The horizontal velocity of the stone thrown horizontally is 25 m/s. Since there is no vertical component to the velocity, the stone will continue to move horizontally at a constant velocity. It will not be affected by gravity in the horizontal direction.

On the other hand, the stone dropped straight down has an initial vertical velocity of 0 m/s. However, due to the force of gravity acting on it, it will accelerate downward at a rate of approximately 9.8 m/s² (ignoring air resistance). The stone dropped vertically will experience an acceleration due to gravity, causing it to accelerate towards the ground.

Now, the time it takes for an object to fall from a given height can be calculated using the equation:

t = sqrt(2h/g)

where t is the time, h is the height, and g is the acceleration due to gravity.

Since the height from which both stones were dropped is the same, we can assume that their heights are equal. Therefore, the time it takes for the vertically dropped stone to hit the ground will be the same for the horizontally thrown stone (time of flight).

Hence, both stones will hit the ground at the same time.

It's important to note that this explanation assumes no air resistance and neglects the horizontal motion of the vertically dropped stone. In reality, air resistance can come into play and slightly affect the time it takes for the stones to hit the ground.