A box is being raised by a fork-lift truck. The weight of the box is $3000\,\text{N}$. The force applied by the fork-lift truck to the box is $3500\,\text{N}$ acting vertically upwards. What is the resultant vertical force on the box?
- A$500\,\text{N}$ downwards
- B$500\,\text{N}$ upwards
- C$6500\,\text{N}$ downwards
- D$6500\,\text{N}$ upwards