Work Done & GPE of a Projectile (without air resistance)

What is Energy?

A fundamental concept in science; present in various forms with endless conversion. Transferred/converted when work is done.

What is Work Done by a Force?

The product of the force and the displacement in the direction of the force (W = Fs).

How is Gravitational Potential Energy (GPE) derived from work done?

Work done by an external force lifting a body against gravity results in a gain in GPE.

What is the equation for Gravitational Potential Energy (GPE) changes in a uniform gravitational field?

ΔE_p = mgΔh.

What is the significance of the absolute value of GPE (E_p = mgh)?

It is arbitrary; the reference point for h can be chosen freely.

What is the important quantity in GPE calculations?

The change in GPE (ΔE_p) due to a change in position, not its absolute value.

What forms of energy does a body possess during projectile motion (without air resistance)?

Kinetic energy (due to speed) and gravitational potential energy (due to position).

What is the principle of Conservation of Energy (without air resistance)?

Any increase in GPE must be accompanied by a decrease in kinetic energy, and vice versa.