Final answer:
The kinetic energy of a bob released from a height can be calculated using its initial gravitational potential energy, which converts to kinetic energy as it falls. Assuming no energy is lost, the kinetic energy at ground level equals the initial potential energy calculated with the mass, acceleration due to gravity, and the height from which it was released.
Step-by-step explanation:
The question involves calculating the kinetic energy gained by a bob as it falls to the ground from a certain height. To determine the kinetic energy of the bob at ground level, we can start by calculating its potential energy at the initial height using the formula gravitational potential energy (GPE) = m × g × h, where m is the mass of the bob, g is the acceleration due to gravity, and h is the height above ground. Assuming that no energy is lost to air resistance or other forms of dissipation, the potential energy will convert entirely to kinetic energy as the bob falls.
For a bob with a mass of 0.18 kilograms released from a height of 45 meters, the initial gravitational potential energy (GPE) would be 0.18 kg × 9.8 m/s² × 45 m. At the ground level, all this potential energy would have been converted to kinetic energy, because the height is now zero and hence the potential energy is zero.
The formula for kinetic energy is KE = ½ × m × v², where v is the velocity at the ground level. But since we do not need to calculate velocity here, we can simply state that the kinetic energy at ground level equals the initial potential energy due to the principle of conservation of energy. So the kinetic energy of the bob at ground level would be the same as the initial potential energy, which can be calculated using the GPE formula provided above.