Question

A chair of mass 15.0 kg is sitting on the horizontal floor; the floor is not frictionless. You push on the chair with a force of 60.0 N that is directed at an angle of 40.0° below the horizontal, and the chair slides along the floor. Use a free-body diagram and Newton’s laws to calculate the normal force that the floor exerts on the chair.

Answer 1

Answer:

$F_n = 185.72 N$

Explanation:

As per FBD we can say that net downward force perpendicular to contact plane must be counterbalanced by the net upward Normal force

So here we will say

$F_n = F sin40 + mg$

now we have

$F = 60.0 N$

$m = 15 kg$

now we have

$F_n = 60 sin40 + 15(9.81)$

$F_n = 185.72 N$

Answer 2

Answer: 185.5672566

Explanation:  The friction is not relevant

Normal reaction is the force perpendicular to the surface.

this force resists the downwards forces applied which are gravity and a component of the applied force.