Questions:

1) A shelf is at a height of 1.8m and a 2kg bowl needs to be placed on the shelf. Calculate the change in gravitational potential energy of the bowl:

2) A 1500kg aircraft increases its altitude from a height of 1200m to 1500m. Calculate the change in gravitational potential energy of the aircraft:

3) What height must a 750kg roller coaster be lifted to if it is to gain 200 kJ of energy?