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