Question

A soccer player kicks a rock horizontally off a cliff 39.6m high into a pool of water. If the player hears the sound of the splash 3.12s later, what was the initial speed given to the rock? Assume the speed of sound in air to be 343m/s.

Answer 1

To calculate the initial speed of the rock, we can use the equation Distance = Speed x Time. The rock falls a distance of 39.6 m in 3.12 s, so the initial speed is approximately 12.69 m/s.

Step-by-step explanation:

To calculate the initial speed given to the rock, we can use the equation:

Distance = Speed x Time

Since the rock was kicked horizontally, its initial vertical speed is 0 m/s. The distance it falls (39.6 m) is equal to the initial speed multiplied by the time it takes to hear the splash (3.12 s).

So, we can rearrange the equation and solve for the initial speed:

39.6 m = Initial Speed x 3.12 s

Initial Speed = 39.6 m / 3.12 s ≈ 12.69 m/s