Question

An apple hanging from a limb has potential energy because of its height . If it falls ,what becomes of this energy just before its hits the ground ? when it hits the ground?

Answer 1

The potential energy of an apple hanging from a tree is converted into kinetic energy as it falls. Just before it hits the ground, almost all of it is kinetic energy. Upon impact, the energy is dissipated mainly as heat, as well as sound or deformation energy.

Step-by-step explanation:

When an apple is hanging from a limb, it has potential energy due to its elevated position above the ground. As the apple falls, this potential energy is converted into kinetic energy (the energy of motion). Just before the apple hits the ground, almost all of its potential energy has been transformed into kinetic energy. When the apple impacts the ground, the kinetic energy is dissipated primarily as heat energy, and some may also manifest as sound energy or even deformation of the apple or the ground, depending on the conditions of the impact.

According to the principle of conservation of energy, the total mechanical energy (sum of potential and kinetic energies) of the apple remains constant during its fall in the absence of air resistance. Therefore, as the apple falls and its height decreases, its potential energy decreases while its kinetic energy increases proportionately. Upon hitting the ground, however, the apple comes to a rest and its kinetic energy becomes zero, which implies that all the energy it had (both potential and kinetic) has been transferred to other forms of energy.

Answer 2

Answer: Just before its hits the ground it becomes kinetic energy and when it hits the ground it becomes in another form of energy (acoustic energy or thermal energy, for example)

Step-by-step explanation:

Energy is the ability of matter to produce work in the form of movement, light, heat, among others.

In this sense, according to the Conservation of Energy principle: "energy is not created or destroyed, it is transformed."

So, in the case of the apple, its total energy is conserved.

When the apple is hanging from a limb, it has zero kinetic energy
`K_(o)=0` (because it is at rest) and has gravitational potential energy
`U_(o)`, which depends on the mass
`m`, the acceleration due gravity
`g` and the height
`h`:

`U_(o)=mgh`

When the apple falls, just before its hits the ground, this gravitational potential energy transforms in kinetic energy
`K_(1)` (since the apple is moving), which depends on the mass and velocity
`V` of the apple:

`K_(1)=(1)/(2)mV^(2)`

When the apple hits the ground, the gravitational potential energy is zero (h=0) and the kinetic energy transforms into some other form of energy (acoustic energy or thermal energy, for example).