A man uses a 2.25-m long wooden board inclined at 35° with the horizontal to raise a 150 kg package. He then pushes forward with a force of 125 N to move the package 4.6 m across a level surface. Find the work done by the man.
NOTE: SHOW YOUR SOLUTION
Solution:
Work done by the man = Force x Distance
Work done = 125 N x 4.6 m = 570 Nm
To calculate the work done in raising the package, we need to calculate the potential energy of the package.
Potential Energy = Mass x Gravity x Height
Height = 2.25 m x sin(35°) = 1.3 m
Potential Energy = 150 kg x 9.8 m/s2 x 1.3 m = 2079 Nm
Total Work Done = 570 Nm + 2079 Nm = 2649 Nm