# Skate Energy

## Work

The product of force and displacement.

*$Work=Force*Distance$*

**Figure:**The work a skateboarder exerts is the product of the force used to propel the rider and the distance the rider travels.

## Energy

The ability to do work.

### Kinetic (KE)

The energy an object has due to it's motion.

- Mechanical
- Thermal
- Sound
- Electrical

### Potential (PE)

The energy an object has due to its position relative to other objects.

- Chemical
- Nuclear
- Gravitational
- Electrical

### Mechanical (ME)

The sum of kinetic and potential energy in an object.

### Thermal (TE)

The energy that comes from friction and heat.

## Energy Conversion

The total energy of an isolated system remains constant. This law means that energy can neither be created nor destroyed.

*$Energ{y}_{initial}=Energ{y}_{final}$*

**Figure:**As the skateboard's position changes, its energy is transferred between potential and kinetic energy. The total amount of energy in the system at all four positions shown below is equal.

## Power

The rate at which work is done or energy is transferred.

*$Power=\frac{Work}{Time}$*

Since work is equal to force times distance,

*$Power=\frac{Force\times Distance}{Time}$*

Velocity is equal to distance over time, thus,

*$Power=ForceXDistance$*

## Energy Transfer

Energy cannot be created nor destroyed, but it can be transformed from one type to another, and from one system to another.

**Figure:** As the board travels down the ramp, its energy is transformed from potential energy to kinetic energy and thermal energy. The magnified view of the skateboard and ramp demonstrates that a small amount of thermal energy is transferred from the board to the ramp as it rolls along its surface.