A $4-$wheel human$-$powered vehicle is ridden by an elite cyclist on a large, flat race track on a still day $($i$.$e$.$

no wind$).$ The vehicle is of a low$-$drag $$streamlined$$ design with a drag coefficient of $0\mathrm{.}25$ based on the

projected frontal area of $0\mathrm{.}5$ m$2$

$.$ The total mass of the vehicle $($including the rider$)$ is $100$ kg$.$ The rolling

resistance of the tyres is constant at $1$ N for each wheel. Ignore all mechanical losses within the vehicle.

$($a$)$ During the race the vehicle travels at constant speed with the rider delivering $350$ Watts of

power to the driving wheel. Calculate the speed of the vehicle.