a) KE/GPE

a) kinetic energy of an object; E_k = ½mv²

b) gravitational potential energy of an object in a uniform gravitational field; E_p = mgh

c) the exchange between gravitational potential energy and kinetic energy

kinetic energy = energy due to an object’s motion

E_k = ½mv²

• kinetic energy (J) = ½ × mass (kg) × velocity² (ms^-1)

gravitational potential energy = energy due to an object’s position in a gravitational field

E_p = mgΔh

• gravitational potential energy (J) = mass (kg) × acceleration of free fall (ms^-2) × change in height (m)

when E_k and E_p are exchanged

• ½mv² = mgΔh

  • loss/gain in E_k = loss/gain in E_p

• v = √2gΔh

  • velocity (ms^-1) = √ 2 × acceleration of free fall (ms^-2) × change in height (m)