What is Normal force: Definition and 470 Discussions

In mechanics, the normal force




F

n





{\displaystyle F_{n}\ }
is the component of a contact force that is perpendicular to the surface that an object contacts, as in Figure 1. In this instance normal is used in the geometric sense and means perpendicular, as opposed to the common language use of normal meaning "ordinary" or "expected". A person standing still on a platform is acted upon by gravity, which would pull them down towards the Earth's core unless there were a countervailing force from the resistance of the platform's molecules, a force which is named the "normal force".
The normal force is one type of ground reaction force. If the person stands on a slope and does not sink into the ground or slide downhill, the total ground reaction force can be divided into two components: a normal force perpendicular to the ground and a frictional force parallel to the ground. In another common situation, if an object hits a surface with some speed, and the surface can withstand the impact, the normal force provides for a rapid deceleration, which will depend on the flexibility of the surface and the object.

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  1. A

    Normal Force at the bottom of a Ferris Wheel

    Homework Statement A student of weight 678 N rides a steadily rotating Ferris wheel (the student sits upright). At the highest point, the magnitude of the normal force N on the student from the seat is 565 N. (a) What is the magnitude of N at the lowest point? If the wheel's speed is...
  2. C

    What Is the Normal Force in Physics Problems?

    Can someone help me with "The Normal Force" 1) Anyone know how to work out these problems? A 42 kg crate rests on a horizontal floor, and a 76 kg person is standing on the crate. (a) Determine the magnitude of the normal force that the floor exerts on the crate. (b) Determine the...
  3. T

    How Do You Calculate Force and Normal Force on an Inclined Plane?

    [SOLVED] Forces and Normal Force Homework Statement In the figure, a crate of mass m = 75 kg is pushed at a constant speed up a frictionless ramp (θ = 32°) by a horizontal force F. The positive direction of an x-axis is up the ramp, and the positive direction of a y-axis is perpendicular...
  4. F

    The Normal Force and Inclined Planes

    Homework Statement A woman pushes her 150kg motorcycle up a slope of 5 degrees with a constant speed of 2 m/s. She achieves this by exerting a force on the bike of 450N parallel to the slope. What is the magnitude of the frictional force acting on the bike? Homework Equations a=...
  5. C

    Normal Force and Static Frictional Force

    Homework Statement A car (m = 1710 kg) is parked on a road that rises 14.7 ° above the horizontal. What are the magnitudes of (a) the normal force and (b) the static frictional force that the ground exerts on the tires? Coefficient of static friction: rubber on dry concrete: 1.0...
  6. F

    How Is the Normal Force Calculated on a Charged Object on Level Ground?

    Homework Statement A small charge of -2 micro-colombs which has a mass of 0.5 kg lies on level ground. A charge of +5 micro-colombs is a distance of 0.35 meters above the charge. What is the magnitude of the normal force in Newtons on the -2 micro-colomb charge? Do not ignore gravity for...
  7. V

    How Do I Calculate Normal Force for a Wooden Block?

    Hello there, I am trying to find the coefficient of friction for a rectangular wooden block. I have the force of friction but I do not know how to find the normal force. The weight of 1 block is 2N. Could someone please explain how I could find the normal force? Would I just multiply 2N by...
  8. T

    Calculating Mass and Normal Force of the Most Massive Car Ever Built

    This is my first time here, so if I put this in the wrong place I am sorry. I will place the entire problem here, exactly as it appears. The most massive car ever built was the official car of the General Secritary of the Communist Party in the former Soviet Union. Suppose this car is...
  9. S

    Normal force acting on an loop?

    Im trying to find the normal force that acts on an roller coaster when going aruond a loop. when the roller coaster is at the top the Fn is always 0 right? And is that the only time its 0?
  10. A

    Calculate the magnitude in Newtons of the normal force

    Homework Statement A plank, of length L = 3.7 m and mass M = 7.0 kg, rests on the ground and on a frictionless roller at the top of a wall of height h = 1.70 m (see the figure). The center of gravity of the plank is at its center. The plank remains in equilibrium for any value of θ >= 74° but...
  11. K

    Normal Force Calculation for Loop-the-Loop Block: Physics Homework Solution

    Homework Statement A small block with mass m=0.100kg can slide along the frictionless loop-the-loop, with loop radius R=0.15m, an initial velocity along the track of vi= 2.0 m/s at point P, at height h=2.0R above the bottom loop. ok now, so first part to the question is, determine the...
  12. K

    Calculating Normal force when object it in circular motion.

    \ P ____T_______ \ / \ \ / \ \ / \ \ / \...
  13. M

    Finding normal force - friction

    Homework Statement the pic is in the attachment. and i am supposed to find the normal force. the object is in equilibrium.The Attempt at a Solution i tried to separate the Fg into its components but the angle is unknown. i can't seem to use any other method. force of friction is unknown and...
  14. P

    Solve Normal Force: 1.4kg Ball Dropped, Find Average Force

    Problem: A 1.4 kg ball is dropped from an unknown height, h, and hits the ground with a velocity of 15.0 m/s and rebounds with a velocity of 11.0m/s. If the ball is in contact with the ground for 1/35 of a second, find the average force the ground applies to the ball. (Use GUESS method.)...
  15. H

    Upward Normal Force Exerted by Floor on Elevator Passenger

    Homework Statement The upward normal force exerted by the floor is 620N on an elevator passenger who weighs 650N. Homework Equations F=ma The Attempt at a Solution I am reviewing all the Homework assigned so, I do got the answers. :) Anyways, the way I set this problem up...
  16. J

    Finding Normal Force on Dolly & Floor Without Mass of Dolly

    I'm uncertain how to find the normal force the floor exerts on the dolly (part B) and the force the dolly exerts on the floor (part C) because the mass of the dolly was not given. ONly the combined mass of the dolly and carton was given. Homework Statement A stock clerk pushes a carton on a...
  17. M

    How Do Normal Forces Affect Various Systems in Physics Problems?

    starting the problem and then direction from there requestedA 38 kg crate rests on a horizontal floor, and a 63 kg person is standing on the crate. (a) Determine the magnitude of the normal force that the floor exerts on the crate. (b) Determine the magnitude of the normal force that the...
  18. T

    Finding normal force from center of gravity

    Homework Statement The figure shows a person whose weight is W = 725 N doing push-ups. Find the normal force exerted by the floor on (a)each hand and (b)each foot, assuming that the person holds this position. Homework Equations center of gravity = cg Xcg = (W1x1 + w2x2 +...)/(w1 +...
  19. I

    Finding the Unknown Mass; Given Tension & Normal Force

    The figure below shows an object of unknown mass m, held by a massless string on a frictionless inclined surface. The angle θ is also uknown. If a tension of magnitude T = 5.8 N and a normal force of magnitude N = 9.7 N act on the object, what is the mass m...
  20. B

    Calculating Normal Force Acting on Car at Point B

    Homework Statement A car with a mass of 1190 kg is traveling in a mountainous area with a constant speed of 78.2 km/h. The road is horizontal and flat at point A, horizontal and curved at points B and C. The radii of curvatures at B and C are: rB = 155 m and rC = 120 m. Calculate the normal...
  21. S

    Normal Force, Static and Kinectic Friction.

    1. A block whose weight is 41.0 N rests on a horizontal table. A horizontal force of 48 N is applied to the block. The coefficients of static and kinetic friction are 0.650 and 0.420 N, respectively. Will the block move under the influence of the force, and, if so, what will be the block's...
  22. B

    Questions About Normal Force and Golf Putting

    I don't understand the normal force and how to calculate it. If I have a question about a golfer putting a ball with a speed and a force that s slowing it down to get to the hole, it has normal force but it would equal 0 because there is no movement in the y direction right?
  23. S

    Exploring the Effects of Applying Vertical Force on Normal Force

    Homework Statement A vertical force F is applied to a block of mass m that lies on a floor. what happens to the magnitude of the normal force N on the block from the floor as magnitude F is increased from zero if force F is a)downward b)upward Homework Equations Let m be the mass of...
  24. G

    Are the Equations for Normal Force on an Inclined Plane the Same?

    Homework Statement I was doing a problem with normal force on an inclined plane and found the normal force by finding the y-component of the gravity vector. Then I also found that if I find the components of the normal force, I can also get another answer. -How are the 2 different equations...
  25. P

    Bead and loop-the-loop: normal force?

    Bead and loop-the-loop: normal force?? Homework Statement A bead sliding around a loop the loop. Given its mass and speed at the top of the loop, we want the normal force on it. Homework Equations mv^2/r = mg + N The Attempt at a Solution I have the correct solution that the...
  26. H

    Position of Normal Force in a Pulled 2D Rectangular Block

    Homework Statement A 2D rectangular block is being pulled at a constant speed with a height of 2.2m and width of 51cm and weighs 403N. The pulling force of 225N is being applied at an 18 degree angle at a height of .666cm from the base of the box. What distance from the lower left corner...
  27. P

    Normal force on a banked curve?

    Normal force on a banked curve? In every textbook I've looked at, I can't find an answer to this question. When determining the centripetal force on an object on a banked curve, it is stated that the banking angle for a given speed and radius is found by tan θ = v^2/rg It is found as...
  28. N

    HELP problem involving force of friction and normal force

    A 2.5 kg block is initially at rest on a horizontal surface. A horizontal force of magnitude F = 6.0 N and a vertical force of magnitude P are then applied to the block. The coefficients of friction for the block and surface are μ_s = 0.40 and μ_k = 0.25. Determine the magnitude of the...
  29. C

    Normal Force in Water and Finding Density

    Hello, Im having trouble with this chapter, So thanks for your patience. Heres how the first question is stated: 1) A 30.0 kg irregularly shaped rock with a density of 4600 kg/m^3 rests on the bottom of a swimming pool. What is the normal force of the pool bottom on the rock? What...
  30. S

    I need the normal force, the force of friction, and her acceleration

    I've got 2 problems: Number 1: Greg is pushing a 32 kg crate across the floor. He is making like difficult by applying his 800 N force down at an angle of 37 degrees below the horizontal. The coefficient of kinetic friction between the crate and the floor is .50. I need to find the normal...
  31. C

    How Does the Normal Force Compare to the Car's Weight in a Circular Valley?

    A car travels at a constant speed of 23 m/s through a small valley whose cross section is like a circule of radius 310 m. What is the magnitude of the normal force on the car, expressed as a multiple of the car's weight? what does it mean by the cross section and how does it relate to the...
  32. V

    Finding normal force with momentum

    Water falls without splashing at a X kg/s from a height H into a bucket of mass M. The bucket sits on a sacle. Determine the reading of the sacle as a function of time. I know the the sum of all forces is equal to the derivative of momentum with respect to time. Mg is the force at time =...
  33. B

    Exploring the Normal Force on a Slanted Slope

    I'm trying to think up situations that will help me understand more complicated situations... Let's say I have: a box on a slanted slope on a chair on the floor The floor exerts a normal force on the chair. But, equal to what? is it: a box m_{1}gcos\theta on a slanted slope m_{2}g on a...
  34. M

    Normal force during a push up problem

    A person whose weight is W = 633 N doing push-ups. l=====x====l==0 ______ _____ 0.885 0.358 Assume L1 = 0.885 m and L2 = 0.358 m. Calculate the normal force exerted by the floor on each hand, assuming that the person holds this position. My work so far: thinking L1 + L2 = 633...
  35. B

    What is the normal force on an object being pushed into another object?

    Is there or what is the normal force on an object being pushed into another object? Example:I push a 10kg box into a 30kg box with a force of 360N and only the second box receives a friction of 240N (the first one receives no friction), what will the acceleration of each of the individual boxes...
  36. M

    Normal Force of a skateboarder at the bottom of a circular ramp

    A skateboard track has the form of a circular arc with a 3.75 m radius. A 47.0 kg skateboarder starts from rest at the top of the circular arc. What is the normal force exerted on the skateboarder at the bottom of the circular arc? I tried using conservation of energy to solve for v mgh=1/2...
  37. mbrmbrg

    Normal force on an inclined plane

    A crate of mass m = 100 kg is pushed at constant speed up the frictionless ramp (theta= 27.0°) by a horizontal force F. What is the magnitude of the force exerted by the ramp on the crate? My x-y coordinate system has x+ pointing up the ramp. I assume that the force in question is the...
  38. P

    Calculating Normal Force on a Box

    Susie has a box that weighs 75N that is lying on top of a horizontal floor that is not frictionless. She pushes on the box with a force of 40N directed at an angle 41 degrees below the horizontal. Calculate the normal force that the floor exerts on the box. -------- We have not learned...
  39. L

    When Does Normal Force on a Wood Block Equal 0?

    Hi. I have a question. When is the normal force on a wood block equal to zero?
  40. C

    Normal force on inclined planes.

    If a car is going up or down an inclined plane, the normal force on the car is just mg cos (theta). However, if a car is turning on an inclined curve, the normal force is mg/cos(theta). Why are the two normal forces not the same? To clarify, here is an example problem: A highway curve...
  41. D

    How Is the Minimum Radius at Point B Calculated for Rollercoaster Safety?

    the question is: The figure below shows the plan for a proposed rollercoaster track. Each car will start from rest at point A and will roll with negligible friction. For safety, it is important that there be at least some small positive normal force (a push) exerted by the track on the car...
  42. H

    Finding Normal Force in Diagram

    http://img477.imageshack.us/img477/8513/diagram0ig.jpg This is a diagram I drew in hopes of making it easier to understand. I'm supposed to find the Normal Force but I really don't understand the concept. I was wondering if someone could help me through it. Thank you!
  43. W

    How can I find the normal force without knowing the applied force?

    Problem: You want to nail a 1.1 kg board onto the wall of a barn. To position the board before nailing, you push it against the wall with a horizontal force F to keep it from sliding to the ground. If the coefficient of static friction between the board and the wall is 0.71, what is the least...
  44. T

    Does a pendulum hanging on a rope has any normal force?

    does a pendulum hanging on a rope has any normal force??
  45. ranger

    What would happen if normal force didnt exist?

    The title says it all. --thank you
  46. E

    Normal Force, Friction Force, Accel problem

    Hi everyone. :) My first post here! Anyway, I have a Physics12AP question that I would like some help with. I've been thinking about it for a long time but I have not been able to solve it. Here's the problem: A car on a horizontal road makes an emergency stop such that all four wheels lock and...
  47. B

    Why does vertical component of normal force

    hi For car to be able to drive trough banked curve on the road with no friction, the vertical component of a normal force must be equal in size but opposite in direction to the force of gravity. Horizontal component F[h] F[h] = m * g * tan(alpha) = m * v^2 / r So there is only one...
  48. A

    How Do You Calculate Frictional Force with Multiple Normal Forces?

    I know that F_f=\mu N where mu is the coefficient of friction. I'm not concerned whether it's kinetic or static now, but I have a problem with the normal force. If I have two normal forces (for example, pushing a mop you have the normal from gravity and the normal from the angle at which the...
  49. 3

    How Do I Solve for the Normal Force in this Cart Problem?

    hi, i know its a really easy thing to figure out normal force or at least i might have been mislead. Here's the problem A cart loaded with bricks has a total mass of 24.9 kg and is pulled at constant speed by a rope. The rope is inclined at 21.8* degrees above the horizontal and the cart...
  50. B

    Calculate Normal Force: 55 N Box on Table with 35 N Box and 28 N Hanging Box

    You have a box that wieghs 55 N sitting on a table. On top of that box there is another box that weighs 35 N attached to a frictionless rope that is around a frictionless pully. At the other end of the rope there is another box that is hanging with a weight of 28 N. What is the normal force that...
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