Answer:
1.52 m
Explanation:
We are given that
Maximum force=F=679 N
Mass of rock ,m=385 kg
Distance,d=0.233 m
We have to find the minimum total length L of the rod required to move the rock.
Torque on rock=[tex]T_1=mgd=385\times 9.8\times 0.233=879.11 N[/tex]
Where [tex]g=9.8m/s^2[/tex]
Torque on man=[tex]T_2=Force\times distance=(L-d)\times 679=(L-0.233)\times 679[/tex]
[tex]T_1=T_2[/tex]
[tex](L-0.233)\times 679=879.11[/tex]
[tex]L-0.233=\frac{879.11}{679}=1.29[/tex]
[tex]L=1.29+0.233=1.523\approx 1.52 m[/tex]
Hence, the minimum total length of rod=1.52 m