Final answer:
The initial kinetic energy of the rock is calculated using the formula KE = ½ mv², where m is the mass and v is the initial velocity of the rock. For example, for a rock with a mass of 0.1 kg and an initial velocity of 15 m/s, the initial kinetic energy would be 11.25 Joules.
Step-by-step explanation:
Initial Kinetic Energy of the Rock
The initial kinetic energy of the rock thrown horizontally off a building is determined by its mass m and its initial velocity v0. The formula for kinetic energy (KE) is given by KE = ½ mv2, so the kinetic energy in this case is ½ m * v02. This equation assumes the body is moving with a velocity v0 and the only form of energy it has at that point is kinetic energy, as it has not started falling under gravity yet and its potential energy is not considered in the question.
Using the provided example, if a rock of mass m is thrown horizontally with a speed v0, we can plug these values into the formula to find its initial kinetic energy. So, if we have a rock with mass m = 0.1 kg (100 g) and it is thrown with an initial velocity of v0 = 15 m/s, the initial kinetic energy would be ½ * 0.1 kg * (15 m/s)2 = 11.25 Joules.