Final answer:
The initial speed with which the stone was thrown upward can be calculated using the principle of conservation of energy.
Step-by-step explanation:
To calculate the initial speed with which the stone was thrown upward, we can use the principle of conservation of energy. When the stone reaches its maximum height, all of its initial kinetic energy is converted into potential energy. At its maximum height, the stone has zero kinetic energy and its potential energy is given by the equation:
PE = mgh
where PE is the potential energy, m is the mass of the stone, g is the acceleration due to gravity (approximately 9.8 m/s^2), and h is the height. In this case, the stone rises to a height of 25 meters. Rearrange the equation to solve for the initial speed:
v = sqrt(2gh)
Substituting the values, we get:
v = sqrt(2 × 9.8 ×25) = 22.1 m/s
Therefore, the stone was initially thrown upward with a speed of 22.1 m/s.