Mathematics 9709/41 — October/November 2018

A particle of mass $0.2\text{ kg}$ moving in a straight line experiences a constant resistance force of $1.5\text{ N}$. When the particle is moving at speed $2.5\text{ m s}^{-1}$, a constant force of magnitude $F\text{ N}$ is applied to it in the direction in which it is moving. Given that the speed of the particle $5$ seconds later is $4.5\text{ m s}^{-1}$, find the value of $F$.