Coefficient of friction, µ=0.5, force applied by person on wall, N=500N Let, mass of the person be m. Here, f1,f2 and w be the friction forces and weight of man respectively. As the person have to be at rest i.e. equilibrium Hence, ‌‌f1+f2=mg and ‌‌f=µN ∴‌‌µN1+µN2=mg Since, ‌‌N1=N2=N=500N ∴‌‌2µN=mg ⇒2×‌