The object's energy changes.

Elastic potential energy is stored in the spring.

The object's gravitational potential energy increases.

Mechanical energy is converted to thermal energy.

The total mechanical energy of the system is not conserved.

Increasing the velocity of an object results in a quadratic increase in its kinetic energy.

The object's energy changes (typically kinetic energy, according to the Work-Energy Principle).

Elastic potential energy is stored in the spring.

The object gains gravitational potential energy.

Mechanical energy is converted to thermal energy, reducing the object's kinetic energy and/or potential energy.

The total energy of the system increases.

A system that allows both matter and energy to be exchanged with its surroundings.

A system that allows energy exchange but not matter exchange with its surroundings.

Work is when a force moves an object over a distance; calculated as $W = Fd$.

The capacity to do work; it comes in many forms (kinetic, potential, thermal, etc.).

The sum of kinetic and potential energy in a system.

Energy of motion; calculated as $K = \frac{1}{2}mv^2$.

Energy due to height above a reference point; calculated as $U_g = mgh$.

Energy stored in a spring or elastic material; calculated as $U_{sp} = \frac{1}{2}kx^2$.

The rate at which work is done or energy is transferred; calculated as $P = \frac{W}{t}$ or $P = \frac{\Delta K}{t}$.