Answer to Question #220168 in Mechanics | Relativity for neba

Question

Determine the magnitude P of the force which the man must exert perpendicular to the handle of the high – pressure washer in order to cause loss of contact at the front support B. note that the operator prevents movement of the wheel with his left foot. The 60-Kg machine has its mass center at point G. Treat the problem as two – dimensional.  

 

Answer 1

$m=60kg$

$W=mg$

For water to loss contact at point B, net torque about point 'O' must be zero i.e

$\sum M_o=0$

$=P(800)-W(125)+R_b(310+125)=0$

When washer is about to loss contact at B, $R_B=0$

So;$P=\frac {60×9.61×125}{800}$

$P=91.96875N$