A person (40 kg) is managing to be at rest between two verticle walls by pressing one wall A by hi hands and feet and the other wall B by his back figure. Assume that the friction coefficient between his body and the walls is 0.8 and that limiting friction acts at all the contacts. a. show that the person pushes the two walls with equal force. b. find the normal force exerted by either wall on the person Take `g=10 m/s^2`.

Explanation

Mass of man = 40 kg, `g=10 m/s^2`
FrictioN/Al force developed between hands, legs and block side with the wall the weight of man. So he remains inequilibrium.
He gives equal force on both the walls so gets equal rectionR from both the walls. If he appies uneuqual forces R should be different the can't rest between the walls.
From the free body diagram

`muR+muR=40g`
`rarr 2muR=40xx10`
`rarr r=(40xx10)/(2xx0.8)=250N`
The normal force =250N`