A 280 lb. barrel is rolled up a 20 ft. ramp to a platform that's 4 ft. tall. What effort is required to move the barrel?

This problem describes an inclined plane and, for an inclined plane, the effort force multiplied by the effort distance equals the resistance force multipied by the resistance distance:
\(F_{e} d_{e}=F_{r} d_{r}\)
Plugging in the variables from this problem yields:
\(F_{e} \times 20 \mathrm{ft}=280 \mathrm{lbs} .4 \mathrm{ft} .\)
\(F_{e}=1120 f t . l b s . / 20 f t=56 l b s .\)