A man of 60 kg standing on a floor at rest. The normal force exerted by the floor on the man is:
A)588 N upward
B) 120 N downward
C) 60 N downward
D) 588 N downward
E) 60 N upward
A)588 N upward
N=mg=60•9.8=588 N
To determine the normal force exerted by the floor on the man, we need to consider the forces acting on the man in the vertical direction.
Since the man is at rest and not accelerating vertically, the sum of the forces in the vertical direction must be zero (according to Newton's First Law of Motion).
The only two forces acting on the man in the vertical direction are the force of gravity and the normal force exerted by the floor. The force of gravity is given by the formula:
Force of gravity = mass × acceleration due to gravity
Given that the mass of the man is 60 kg and the acceleration due to gravity is approximately 9.8 m/s^2, we can calculate the force of gravity:
Force of gravity = 60 kg × 9.8 m/s^2 = 588 N
Since the force of gravity is acting downward, the normal force exerted by the floor must be equal in magnitude but opposite in direction to counteract the force of gravity.
Therefore, the correct answer is:
C) 60 N downward
To determine the normal force exerted by the floor on the man, we need to understand the concept of normal force. The normal force is the force exerted by a surface to support the weight of an object resting on it. It acts perpendicular to the surface.
In this case, the man is standing on a floor at rest, which means there is no vertical acceleration. Since the man is not sinking into the floor or accelerating upwards, the normal force exerted by the floor on the man must be equal in magnitude and opposite in direction to the gravitational force acting on the man.
To find the gravitational force acting on the man, we can use the formula:
Weight = mass × gravity
where mass is the mass of the man and gravity is the acceleration due to gravity, approximately 9.8 m/s².
Weight = 60 kg × 9.8 m/s² = 588 N
Therefore, the normal force exerted by the floor on the man is 588 N.
So, the correct answer is:
A) 588 N upward