Calculate Normal Force: Crate & Person on Floor

In summary, the conversation discusses determining the magnitude of normal forces exerted on a 41 kg crate by a horizontal floor and a 67 kg person standing on the crate. The equations (m1+m2)G and M2(G) are mentioned, and the values of 1080 and 670 are calculated for the normal forces. The correct value of 9.8 m/s^2 is noted for the force of gravity and the importance of specifying units is emphasized. It is also mentioned that using an approximation of 10 for the force of gravity may affect the accuracy of the answers.
  • #1
Pizza Dave
1
1

Please help with below. is it correct?

A 41 kg crate rests on a horizontal floor and a 67kg person is standing on the crate.

a. determine the magnitude of the normal force the floor exerts on the crate

b. determine the magnitude of the normal force that the crate exerts on the person

Homework Equations



(m1+m2)G
M2(G) [/B]

The Attempt at a Solution



a. 1080
b. 670 [/B]
 
  • Like
Likes carl_loves_math
Physics news on Phys.org
  • #2
Try drawing a force diagram for both the person on the crate and the crate and try summing your forces for each individually. The answers should become clear!Also, this belongs in introductory physics.
 
  • #3
AlephNumbers, this was an impertinent response.

Pizza Dave, you calculated this answer correctly, but it looks like you substituted 10 for the force of gravity instead of the actual value of 9.8. This may help your answers be more accurate in the future!
 
  • #4
Pizza Dave said:
a. 1080
b. 670
You should always specify units (unless instructed otherwise).
carl_loves_math said:
it looks like you substituted 10 for the force of gravity instead of the actual value of 9.8.
Both values are just approximations. Often students are told to use 10 ms-2. On the other hand, if it is approximated to 10 then, logically, the answers should only be given to the same precision, e.g. 1100 N for (a).
And you mean gravitational acceleration, not force.
 

1. How do you calculate the normal force on a crate and person on a floor?

To calculate the normal force on a crate and person on a floor, you will need to use the formula FN = mg + ma, where FN is the normal force, m is the mass of the crate and person, g is the acceleration due to gravity, and a is the acceleration of the crate and person. This formula takes into account both the weight of the crate and person and any additional acceleration caused by external forces such as friction.

2. What is the normal force?

The normal force is the force exerted by a surface on an object in contact with it. It is always perpendicular to the surface and acts to support the weight of the object and prevent it from falling through the surface.

3. How does the normal force affect the motion of an object?

The normal force is a reactive force that balances out the weight of an object and any additional external forces acting on it. This means that the normal force can affect the motion of an object by either supporting it and keeping it stationary, or by balancing out the forces and allowing it to move in a certain direction.

4. Is the normal force always equal to the weight of an object?

No, the normal force is not always equal to the weight of an object. It is only equal to the weight when the object is at rest or moving at a constant velocity. If the object is accelerating, the normal force will be greater than the weight to balance out the additional forces causing the acceleration.

5. How does the normal force change with the angle of incline?

The normal force changes with the angle of incline because the weight of an object is distributed differently on an inclined surface compared to a flat surface. As the angle increases, the normal force decreases because more of the weight is acting parallel to the surface and not perpendicular to it. At a 90 degree angle, the normal force is equal to 0 because the weight is fully parallel to the surface.

Similar threads

  • Introductory Physics Homework Help
Replies
1
Views
2K
  • Introductory Physics Homework Help
Replies
13
Views
4K
  • Introductory Physics Homework Help
Replies
5
Views
6K
  • Introductory Physics Homework Help
Replies
14
Views
5K
  • Introductory Physics Homework Help
Replies
3
Views
2K
  • Introductory Physics Homework Help
Replies
5
Views
1K
  • Introductory Physics Homework Help
Replies
5
Views
9K
  • Introductory Physics Homework Help
Replies
2
Views
2K
  • Introductory Physics Homework Help
Replies
12
Views
5K
  • Introductory Physics Homework Help
Replies
24
Views
2K
Back
Top