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.
1. A m = 3.0 kg wood box slides down a vertical wood wall while you push on it at a θ = 49° angle. What magnitude of force should you apply to cause the box to slide down at a constant speed?
2. Fk-Mk*n
3. i know there are 4 forces acting on the object. gravity, normal force from the...
Homework Statement
A chemistry student with a mass of 75 kg is riding a steadily moving Ferris wheel. When she is at the top of the Ferris wheel, the normal force from the seat on to her body has a magnitude of 567 N.
What is the magnitude of the normal force on her body when she is at...
how large is the normal force? (applying Newtons laws phys 1111)
A 23 kg child goes down a straight slide inclined 38 degrees above horizontal. The child is acted on by his weight, the normal force from the slide, kinetic friction, and a horizontal rope exerting a 30 N force as shown in the...
I'm bypassing the normal questions, only because I have already solved the question, but want help figuring out why the answer is what it is (without incorporating numbers into it at all).
The idea is that a car is at the top of a hill going a constant speed. We are to treat the hill as having...
Homework Statement
A horizontal force of 100 N pushes a 12-kg block up a frictionless incline that makes an angle of 25° with the horizontal. (Use g = 9.81 m/s2.)
1. What is the normal force, in Newtons, that the incline exerts on the block? Round your answer to two significant figures...
1. Hi, I've been reading through an introductory physics book and am having trouble understanding certain equations pertaining to centripetal force. The part of the book I am on is discussing banks and how they are used to create centripetal force on roads. It's been stumping me for months...
At the airport, you pull a 21.9-kg suitcase across the floor with a strap that is at an angle of 46.1° above the horizontal. Calculate the normal force in the strap, given that the suitcase moves with constant speed and that the coefficient of kinetic friction between the suitcase and the floor...
A Mercedes-Benz 300SL (m = 1700 kg) is parked on a road that rises 20° above the horizontal.
(a) What is the magnitude of the normal force?
(b) What is the static frictional force that the ground exerts on the tires?
Homework Equations
FN=Wcos(theta)
Wsin(theta)=Framp
(at least that's...
http://users.on.net/~rohanlal/roll.jpg
A roller-coaster car has a mass of 494 kg when fully loaded with passengers.
If the car has a speed of 12.5 m/s at point A, what is the force exerted by the track on the car at this point?
To solve this don't i need to determine what the downward...
I'm having problems with my initial approach on this problem:
The figure below shows four choices for the direction of a force of magnitude F to be applied to a block on an inclined plane. The directions are either horizontal or vertical. (For choices a and b, the force is not enough to lift...
Homework Statement
A car is on a banked curve of bank angle 18 deg, radius 70m. It's mass is 1020kg. Draw a free body force diagram approximately to scale, when the car is at the 'design speed'. What is meant by design speed? Find the resultant force and the normal force n.
Homework...
Homework Statement
What is the magnitude of the normal force of the table on the lower magnet?
(so there is a table with a magnet on top and below its surface)
Homework Equations
The Attempt at a Solution
So i was wondering if someone could help me figure out all of the forces acting...
hello, I'm trying to study for the mcat, and I have a conceptual question about normal force, mg, and centripetal force during a loop-de-loop on a roller coaster.
Could you validate these force equations?
1. At the very bottom of the loop:
N - mg = ma = mv^2 / r
N = mg + ma
2. At the...
Homework Statement
A rock of mass M with a density twice that of water is sitting on the bottom of an aquarium tank filled with water. The normal force exerted on the rock by the bottom of the tank is?
Homework Equations
The Attempt at a Solution
The answer is Mg/2, I...
Homework..urgent help
1.) If a woman lifts a 19.2 kg bucket from a well and does 6.83 kJ of work, how deep is the well? Assume that the speed of the bucket remains constant as it is lifted.
2.) A constant force of 38.3 N, directed at 26.9° from horizontal, pulls a mass of 12.1 kg horizontally...
Homework Statement
The 63 kg climber in Fig. 4-52 is supported in the "chimney" by the friction forces exerted on his shoes and back. The static coefficients of friction between his shoes and the wall, and between his back and the wall, are 0.83 and 0.55, respectively. What is the minimum...
Homework Statement
Three blocks rest on a frictionless, horizontal table (see figure below), with m1 = 8 kg and m3 = 15 kg. A horizontal force F = 104 N is applied to block 1, and the acceleration of all three blocks is found to be 3.2 m/s2.
Homework Equations
W=mg
F=ma
Normal...
Unfortunately, I'm totally lost on this question. I read the topic in the archive, and I know I can't ask for an answer to this, and frankly I don't want one. But is someone able to give me the process for doing this?
Homework Statement
A cart loaded with bricks has a total mass
of 24.3 kg...
Homework Statement
If:
weight = m
speed = v
angle = theta
radius = r
Write an algebric expression that is equal to the Normal force
Homework Equations
F = ma
acentr. = v2/r
The Attempt at a Solution
N -mgcos(theta) = m v2/r
N = m v2/r +mgcos(theta)
correct?
Homework Statement
What is the normal force acting upon a person at the top of a ferris wheel that has a radius of 60 meters, and is traveling at a rate of 25 meters/second?
Homework Equations
Centripital acceleration = velocity²/radius
Centripetal Force = Gravity Force - Normal Force...
Homework Statement
Starting from rest, a 5.85 kg block slides 2.07m down a rough 26.4degree incline. The coefficient of kinetic friction between the block and the incline is 0.427. The acceleration of gravity is 9.8m/s^2. Find the work done by the normal force. Answer in units of Joules...
Homework Statement
How do you find the normal force and acceleration of a 72 N block that is pulled across the floor with tension force of 33 degrees. As is slides the coefficient of kinetic friction between object and the floor is 0.32.
Homework Equations
The Attempt at a Solution
Homework Statement
An airplane is taking off at an acceleration of 3.5 m/s2at an angle of 45 degrees relative to the horizontal. Find the Normal force and its direction that is acting on the pilot if the mass of the pilot is 50 kg.
Homework Equations
The Attempt at a Solution...
Homework Statement
A 9940 kg plane in an air show completes a vertical loop of radius 596 meters at 155 m/s. What normal force does the airplane seat exert on the 92 kg pilot at the top of the loop and at the bottom of the loop.
Homework Equations
Top of loop
m(v^2/r)= Fnormal + mg...
Homework Statement
A 41 kg crate rests on a horizontal floor, and a 53 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 crate exerts on the person...
Homework Statement
Three blocks are arranged in a stack on a frictionless horizontal surface. The bottom block has a mass of 37.0 kg. A block of mass 18.0 kg sits on top of it and a 20.0 kg block sits on top of the middle block. A downward vertical force of 170 N is applied to the top block...
This has always puzzled me, the normal force, and I think I might understand this now, or at least part's of it.
So here's the case: there's a plank of wood leaning against a wall.
If it's not slipping/sliding or any of the sort, then there is no movement in the x or y direction.
Then...
In a problem whereby you want to calculate the net force of the rope lifting a box, and there is something in the box, whether you take into account the normal force.
The forcees would be the tension of the rope, and the weight of the box and the object inside. To caculate the net force of the...
Homework Statement
A 30 kg box is on a frictionless floor. The box is being pulled with a force of 120 N at an angle of 15 degrees. Find the normal force. Why is the normal force not equal to simply the gravitational force. What would make the person pull the box vertically into the air...
Homework Statement
The diagram below shows the forces acting on a block moving at a constant velocity down an inclined plane. The weight of the block, Fw, can be resoled into two components, one parallel to the surface of the plane, Fll, and one perpendicular to the surface of the plane, F_l_...
On an inclined plane, "\SigmaFy = N - mg cos ø = ma = 0".
And "\SigmaFx = mg sin ø = ma" (frictionless).
So, in the y direction, "N = mg cos ø".
But on a banked curve, "\SigmaFy = N cos ø - mg = ma= 0".
And "\SigmaFx = N sin ø = ma = mv²/r" (frictionless).
So, in the y direction, "N cos...
Homework Statement
The 68 kg climber in Fig. 4-52 is supported in the "chimney" by the friction forces exerted on his shoes and back. The static coefficients of friction between his shoes and the wall, and between his back and the wall, are 0.78 and 0.55, respectively. What is the minimum...
Homework Statement
There is an object glued on a plate that rapidly accerlates upwards (then stops) and then accelerates downwards. Graph the y-component of the normal force on a force vs. time graph. There is an interval of time on the graph inwhich the normal force is negative. How can this...
Problem: A small block of mass m rests on the rough, sloping side of a triangular block of mass M which itself rests on a horizontal frictionless table. If the coefficient of static friction is u determine the minimum horizontal force F applied to ramp M that will cause the small block m to...
How do i calculate a normal force when gravity is not the only force involved??
Dear everyone,
This is my first post on the physics forum and I have a problem which I think relates to calculating the normal force (perhaps I'm wrong).
I'm programming a game and I have a particle which has a...
An adult is pulling two small children in sleigh over level snow. The sleigh and the children have a total mass of 47 kg. The sleigh rope makes an angle of 23 with the horizontal, The coefficient of kinetic friction between the sleigh and the snow is 0.11. Calculate the magnitude of the tension...
Hi, I thought I had some sort of an understanding in physics until I came across these two websites. On the first page the person in the air exerts a force on the rope but for the rope and person to stay still another force must be exerted by person number two hence the doubling of the force on...
Homework Statement
Lets say that a person called A rides his motorcycle. When this person turns, he tilts his motorcycle on a horizontal road. Is the normal force still normal to the surface or does it point in the same direction as the person sitting on the bike?
The Attempt at a Solution...
Homework Statement
"A crate of mass 50 kg is pushed across a frictionless horizontal floor with a force of 100N directed 23.5 degrees below the horizontal. The magnitude of the normal force of the floor on the crate is:"
Homework Equations
F = ma? Not sure what else would apply...
Hi,guys ...i have a question in my mind always confused me just like Newton 3rd law but this one is different.
here is my question.
I always confuse with the normal force and weight force which is mass * gravity.
for example let's say a coin tossed straight upward,and reaches its highest...
Homework Statement
Here's the situation:
A jet pilot puts an aircraft with a constant speed into a vertical circular loop. If the speed of the aircraft is 700 km/h and the radius of the circle is 2.0 km, calculate the normal forces exerted on the seat by the pilot at the bottom and top...
Homework Statement
The drawing shows a person (weight W = 581 N, L1 = 0.829 m, L2 = 0.399 m) doing push-ups. Find the normal force exerted by the floor on each hand and each foot, assuming that the person holds this position.
http://img401.imageshack.us/img401/3044/p911zz6.gif...
I know that the force of friction is the (coefficient of friction) x (normal force). My question is, why isn't area involved? That is, why wouldn't a larger surface have more friction than a smaller surface, if the normal force is the same?
PS: Sorry, just in case this is in the wrong section
I am a new user so if I am violating any rules I apologize
If we have a mass on an inclined plane ,
Does the Normal force depend on Coordinate used. i.e coordinate system along rod( tilted one) and coordinate system in the regular way
I know the answer is " NO" but I get
N=...
Homework Statement
Three rectangular blocks of equal mass m slide to the right along a frictionless horizontal surface accelerated by a force F applied to the left side of the left-most block. (a) Draw a free-body diagram for each block. (b) Determine the magnitudes and directions of all of...
Homework Statement
A 70kg climber is suppored in a "chimney" by the friction forces exerted on his back and shoes. The coeffcients of static friction of his feet against the wall and his back against the wall are 0.8 and 0.6 respectively. What is the minimum normal force he needs to apply to...
Homework Statement
A boy pulls a 50kg crate across a level floor with an applied force of 200N. If this applied force is at an angle of 30 degrees with the horizontal and the coefficient of kinetic friction is .3, determine;
a) the normal force exerted on the crate by the floor.
I...