A boy of mass 40kg is climbing a vertical pole at a constant speed. If the coefficient of friction between his palms and the pole is 0.8 and g=10m/s2, the horizontal force that he is applying on the pole is
The coefficient of friction =0.8,g=10m/s, mass =40kg
The frictional force =μN
Hence, μN=mg⇒N=mgμ
=40×100.8=500N