Question

An object with a mass of 5 kg lies is on a horizontal surface with a coefficient of kinetic friction of 0.75. A force of 30 Nis applied to it DOWNWARDS, perpendicular to the surface, a force of 40 N is applied to it at an angle of 30 degrees above the +x axis, and a force of 20 N is applied to it in the negative x direction. The mass moves 10 m in the positive x direction with these forces applied. What is the work done by just the normal force? F2 F3 300 FIV 7.130 -742.88) 0) -442.880

Answer 1

Solution:

Normal force always acting perpendicular  to the displacement.

Now we know that work done = force x  displacement x cos(angle between force and displacement)

so work done by only normal force = force x displacement x cos 90^o = 0 ( as cos90^o= 0 )

so work done by only normal force = 0 J

Answer : 0 J

Thank You.