Final answer:
The kinetic energy of the ball just before it hits the ground is 49 Joules, which is equal to its initial gravitational potential energy from a height of 5 meters, taking into account that energy is conserved and that the only force doing work is gravity.
Step-by-step explanation:
The question asks to find the kinetic energy of a ball just before it hits the ground, assuming it was dropped from a height of 5 meters. To solve this problem, we use the conservation of energy principle, as follows:
Initial Energy (at height h) = Potential Energy (PE) = m × g × h = 1 kg × 9.8 m/s² × 5 m = 49 Joules
Before the ball hits the ground, its gravitational potential energy will have been converted into kinetic energy, neglecting air resistance. Therefore, the kinetic energy (KE) just before impact will be equal to the initial potential energy.
So, the kinetic energy (KE) just before the ball reaches the ground is 49 Joules.
To calculate the kinetic energy of a body in motion, use the equation KE = 0.5 × m × v², where 'm' represents mass and 'v' is the velocity. Since we do not need to find the velocity in this problem, we directly use the conversion from potential to kinetic energy due to the conservation of energy in a system where the only force doing work is gravity.