Forces and equilibrium — practice question

A particle of mass $0.2\,\text{kg}$ travels along a straight path and is acted on by a constant resistive force of $1.5\,\text{N}$. At the moment its speed is $2.5\,\text{m s}^{-1}$, a constant force of magnitude $F\,\text{N}$ is applied in the direction of motion. If its speed $5$ seconds later is $4.5\,\text{m s}^{-1}$, determine the value of $F$.