Put the ideas to work.

An athlete and racing wheelchair have a combined mass of $84.0\,\mathrm{kg}$. At the start of a straight training run, the wheelchair is already moving at $2.00\,\mathrm{m\,s^{-1}}$. For the next $1.50\,\mathrm{s}$, the athlete produces a constant forward driving force of $420\,\mathrm{N}$. A constant rolling resistance of $84.0\,\mathrm{N}$ acts backward. After this $1.50\,\mathrm{s}$ push, the athlete stops producing a driving force. Assume the rolling resistance remains $84.0\,\mathrm{N}$ until the wheelchair stops. (a) Calculate the resultant force and acceleration during the push. [3] (b) Calculate: (i) the speed at the end of the push; (ii) the distance travelled during the push. [4] (c) Calculate the acceleration after the driving force is removed. [2] (d) Calculate: (i) the time taken to stop after the push; (ii) the distance travelled after the push. [3] (e) Calculate the total distance travelled from the start of the stated motion until the wheelchair stops. [1]