A worker pushes a barrel with weight $2000\,\text{N}$ up a plank that is $2.0\,\text{m}$ long and into a lorry. The rear of the lorry is $0.80\,\text{m}$ above the flat road surface. What amount of work is done on the barrel against gravity?
- A$1000\,\text{J}$
- B$1600\,\text{J}$
- C$2500\,\text{J}$
- D$4000\,\text{J}$