A museum has a hanging model of mass 1.5 kg. During maintenance, the model is lowered.
| Position | Height above the floor in m\mathrm{m}m |
|---|---|
| before maintenance | 6.0 |
| after maintenance | 2.0 |
Use g=10 N/kgg=10\ \mathrm{N/kg}g=10 N/kg.
What is the decrease in the gravitational potential energy of the model?
6.0 J6.0\ \mathrm{J}6.0 J
60 J60\ \mathrm{J}60 J
90 J90\ \mathrm{J}90 J
40 J40\ \mathrm{J}40 J