$1-$ A wheeled tractor weighing $120$ tons is being operated on a haul road $($loose sand$)$ with a tire penetration of $3in.$ Determine the rolling resistance of this truck in $lb.$ Assume the tractor has narrow$-$tread tires.

$2-$ A wheel tractor$-$scraper weighing $90$ tons is being operated on a rutted dirt roadway with a tire penetration of $1in.$ Assume the scraper has narrow$-$tread tires. Calculate the following:

the total resistance when the scraper is ascending a slope of $3\%.$

the equivalent slope when the scraper is ascending a slope of $3\%.$

the total resistance when the scraper is descending a slope of $2\%.$

the equivalent slope when the scraper is descending a slope of $2\%.$