Understanding the Concepts
* Kinetic Energy (KE): The energy an object possesses due to its motion. It's calculated as KE = (1/2) * m * v^2, where:
* m = mass of the object
* v = velocity of the object
* Potential Energy (PE): The energy an object possesses due to its position relative to a reference point. For objects near the Earth's surface, PE = m * g * h, where:
* m = mass of the object
* g = acceleration due to gravity (approximately 9.8 m/s²)
* h = height above the reference point
Solution
1. Conservation of Energy: As the rock falls, its potential energy (PE) is converted into kinetic energy (KE). Therefore, we can say:
PE (at height) = KE (at ground)
m * g * h = (1/2) * m * v^2
2. Solving for Velocity: We need to find the velocity (v) of the rock just before it hits the ground. We can rearrange the conservation of energy equation to solve for v:
v² = 2 * g * h
v = √(2 * g * h)
v = √(2 * 9.8 m/s² * 10 m)
v ≈ 14 m/s
3. Calculating Mass: Now that we know the velocity, we can use the kinetic energy formula to solve for the mass:
KE = (1/2) * m * v²
33000 J = (1/2) * m * (14 m/s)²
m = (2 * 33000 J) / (14 m/s)²
m ≈ 33.9 kg
Therefore, the mass of the rock is approximately 33.9 kg.