Normal force Definition and 468 Threads

"If there's no normal force, there's no contact." Is the statement above correct? What is the relationship between contact and the existence of normal force? Are they necessary and sufficient conditions to each other? Thanks for your help :p

Homework Statement A woman pulls on her suitcase with a force of 105N at an angle of 38 degrees above the horizontal. The coefficients of static and kinetic friction between and suitcase and the floor are 0.273 and 0.117. The mass of the suitcase is 36 kg. what is the magnitude of the normal...

Homework Statement It includes a diagram so i just took a screenshot of the question. I don't undertand how to do this problem Thanks

I'm feeling really stupid right now. But let's say a block is resting on a floor with friction. If someone were to pull to the right of the box at some angle theta above the horizontal, there would be components in the y (perp. to horizontal) and x (parallel to horizontal) of the force you pull...

Homework Statement A pizza box thrown across the room strikes the floor with a horizontal velocity of 2.0 m/s. Homework Equations If the 300-g box encounters a floor with a coefficient of kinetic friction of 0.3, how far will the box slide before coming to rest? The Attempt at...

A woman is riding a Jet Ski at a speed of 26 m/s and notices a seawall straight ahead. The farthest she can lean the craft in order to make a turn is 22°. This situation is like that of a car on a curve that is banked at an angle of 22°. If she tries to make the turn without slowing down, what...

A 75 kg person is standing on a bathroom scale in an elevator. The scale is calibrated to read in Newtons. The elevator is accelerating upward at 135 m/s2. What is the reading on the scale? What apparent value of g does the man give? The Free Body Diagram Normal on the man, upward...

While moving in, a new homeowner is pushing a box across the floor at a constant velocity. The coefficient of kinetic friction between the box and the floor is 0.41. The pushing force is directed downward at an angle θ below the horizontal. When θ is greater than a certain value, it is not...

Homework Statement A 1160 kg car is held in place by a light cable on a very smooth (frictionless) ramp, as shown in the figure . The cable makes an angle of 31.0 degrees above the surface of the ramp, and the ramp itself rises at 25.0 degrees above the horizontal. Find the normal force along...

Homework Statement 4 questions: 1. A block of mass M=2.6 kg is dragged over a horizontal surface by a force F=22.0 N. The block is displaced a distance d=10.0 m, the friction force Ff is 3.1 N. What is the weight of the block in Newtons? Use 10 m/s2 for g. 2. A block of mass M=1.0 kg is...

The problem states: A horizontal force of 77 N pushes a 12 kg block up a frictionless incline that makes an angle of 60 degrees with the horizontal. What is the normal force that the incline exerts on the block? After drawing the FBD I can see there are only 2 forces acting in the Y...

Homework Statement The attachment shows the problem. The normal force at the top of the loop is 3 g's (as in g-force). Homework Equations PE = mgh KE = .5mv2 Fc = \frac{mv2}{r} PE + KE = PE' + KE' v = \sqrt{2gh} The Attempt at a Solution The normal force would be: 30 * mass...

Hi, :smile: As I was going through some SHM problems I came across a doubt regarding normal forces. Let's use as an example a book standing on a table: There are two forces acting on the book: It's weight acting downwards and a normal reaction force from the table acting upwards. My doubt...

Homework Statement The total weight of the go-cart and driver is 1068N. The location of their combined center of mass is shown in attachment. The rear wheen exert a 106.7 N horizontal force together on the track. Neglect horizontal force on the front wheels. a) What is go carts...

Hints please! :) friction, normal force Please, can someone give me hints on how to look at this problem? I'd really like to uncover this problem myself, so please do not give away the answer to me! :D You can see the drawing here, on problem 66...

A bead slides without friction around a loop-the-loop. The bead is released from rest at h=3,5R. a) What is the speed at point A? b) How large is the normal force at point A if its mass is m=5g?------------------------------------------------------- My question for: a) Do we consider the...

Homework Statement Prove that normal force between a block and wedge is: N = m*sqrt(g^2-a^2) Homework Equations I used the pythagorean theorem to attempt this. The Attempt at a Solution See attached. Am I doing this right, or am I making up math here to fit the answer?

I am learning uniform circular motion and the question says: A child on a sled comes flying over the crest of a small hill. His sled does not leave the ground but he feels the normal force between his chest and the sled decrease as he goes over the hill. Explain. Now, I know that normal force...

For the following question, I am given the weight of a ball being twirled on a string, the radius of the string, and the velocity. And I am asked to calculate the tension of the string when the ball is at the top of it's path, and the bottom of it's path. I know that tension is a centripetal...

A roller coaster car of mass 960 kg starts at a distance of H = 20 above the bottom of a loop 12 m in diameter. If the friction in negligible, find the normal force of the rails on the car when i it is a) pside down the top of the loop and b) at the bottom of hte loop i have no idea how to do...

A 69.2-kg skier encounters a dip in the snow's surface that has a circular cross section with radius of curvature of r = 13.2 m. If the skier's speed at point A in the figure below is 8.13 m/s, what is the normal force exerted by the snow on the skier at point B...

Homework Statement We have a block of wood that has a weight of 95.5g lying on another flat piece of wood. The block of wood has a string attached to a tray that hangs over a pulley. Wehad to add weight to the block adn then to the tray to see how much weight in the tray would break the...

Homework Statement In the figure, a crate of mass m = 107 kg is pushed at a constant speed up a frictionless ramp (θ = 32°) by a horizontal force http://edugen.wiley.com/edugen/shared/assignment/test/session.quest1510980entrance1_N10037.mml?size=14&rnd=1298229739658 .[/URL] The positive...

Homework Statement A dated box of dates, of mass 5.00 kg, is sent sliding up a frictionless ramp at an angle of θ to the horizontal. The figure below gives, as a function of time t, the component vx of the box's velocity along an x-axis that extends directly up the ramp. (The vertical axis...

My instructor told the class to keep in mind that we should only account for normal force when friction is involved in the problem. In my book there is a problem in which friction is negligible and they account for normal force, but ultimately the normal force has no effect on the conclusion of...

Homework Statement Your moving company runs out of rope and hand trucks, so you are forced to push two crates along the floor. The crates are moveing at constant velocity, their masses are m1=45kg and m2=22kg, and the coefficient of kinetic friction between both crates and the floor are 0.35...

Homework Statement A box sits on an inclined plane. Given its mass and the angle of the incline, what is the magnitude of the normal force? Homework Equations I don't know- my understanding is N=mgcos(theta), but my physics textbook says otherwise... The Attempt at a Solution My attempt at...

Homework Statement A book rests on a table. Identify the NIII force pairs. Homework Equations The Attempt at a Solution Downward force of book on table; upward force of table on book (N). Downward force of book and table on ground; upward force of ground on book and table (N)...

This is my first year teaching High School Physics and I'm finding there are a lot of questions I should have asked 25 years ago when I was in college. 1. Does anybody know what the coefficient of friction is based on? Usually these things are based on something like getting units to cancel...

When a mass is on a surface,It applies a force to it because of its weight.According Newton's 3rd law,the surface applies a force to the mass.Can we call this force,Normal force?

Homework Statement A box is being pushed across the floor with a 250 N force directed 20ο below the horizontal. Is The normal force is larger than the weight of the box? True or False. Explain. Homework Equations sin(20) = opp/hyp The Attempt at a Solution Fn = 250sin(20o) + Fg Please...

Homework Statement There is a roller coaster cart with passengers sitting on the top of a 23 degree incline. The ride is about to start. The combined mass of the cart and passengers is 363kg. a) What would the free body diagram look like? b) How do you solve for normal force? c) How do...

"A roller coaster car does a loop-the-loop. When it is upside down at the very top, which of the following is true?" The normal force and the weight are in opposite directions. The normal force and the weight are perpendicular to each other. The weight is zero. The normal force...

Homework Statement A person whose weight is W = 587 N doing push-ups. Assume L1 = 0.817 m (Centre of Gravity to Feet) and L2 = 0.414 m. (Centre of Gravity to Hands) Calculate the normal force exerted by the floor on each hand (enter first) and each foot, assuming that the person holds this...

Homework Statement http://img24.imageshack.us/img24/7550/12929005.png Homework Equations The Attempt at a Solution I don't think the normal force depends on mass so I wouldn't know how to rank I mean the normal force on the middle bottom and left bottom is the same so how can I rank?( i mean...

Homework Statement a person is doing pushups and its weight is 584 N, center of gravity is at waist and from waist to hands=.410m and from waist to feet=.840m. find the normal force on each hand and each foot Homework Equations The Attempt at a Solution do u have to find the...

Homework Statement A small sphere A of radius r and mass m rolls without slipping inside a large hemispherical bowl of radius R. The sphere A starts from rest at the top point on the rim of the hemisphere. Find the normal force exerted by small sphere when it touches the bottom of the...

I just made up this question to understand how normal force works: Let's say mass A = 20 kg and it's on a flat surface. The normal force = 20g But what happens when you put mass B on top of mass A? mass B = 10kg Does mass A have the same normal force, or does the normal force equal...

Homework Statement A three-tiered birthday cake rests on a table. From bottom to top, the cake tiers weigh 16 N, 9 N, and 5 N, respectively. What is the magnitude and direction of the normal force ating on the second-tier? Homework Equations FN=FWcos(theta) The Attempt at a Solution...

Homework Statement A car moving at 13.5 m/s encounters a bump that has a circular cross-section with a radius of 56.8 m. What is the normal force exerted by the seat of the car on a 70.8 kg passenger when the car is at the top of the bump? v = 13.5 r = 56.8 m = 70.8kg Homework...

Homework Statement A compressed spring is released pushing a block at rest along a level, frictionless path. This is Location 1. The block then passes over a small area of friction which ends and becomes frictionless again. This is Location 2. The block then enters a loop-the-loop in the...

a body of 5 kg mass is resting on a board which is gradually tilted until, at an angle of 30 degrees to the horizontal, the body begins to move down the plane. find coefficient of friction and magnitude of the normal and frictional forces when the body begins to slip. i managed to workout...

Hi everyone. I just started learning some basic Newtonian mechanics and several questions arose. Hope you could help me with it. Thank you. 1. What exactly constitutes the "normal force". It says that normal force is perpendicular to the surface where the object is placed but I...

Homework Statement An 1850 kg car passes over a bump in a road that follows the arc of a circle of radius 40.60 m as seen in the figure below. a) What force does the road exert on the car as the car passes the highest point of the bump if the car travels at 14.9 m/s? b) What is the maximum...

A 330-kg piano slides 3.6 m down a 28º incline and is kept from accelerating by a man who is pushing back on it parallel to the incline. The effective coefficient of kinetic friction is 0.40 what is the work done by the normal force? If someone could let know how to find FN, would it...

Hey guys, I was wondering if you can help tell me if I am doing this right for finding the parallel and perpendicular force. To find the parallel force would I have to take: gravity*sin(theta) or would I have to take the weight? Same goes with the perpendicular force, but using cosine...

Homework Statement 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, and kinetic friction. How large is the normal force of the slide on the child? _?_ Newtons

Homework Statement Hi. I have this problem: A particle of mass m, rests on top of a frictionless sphere of radius R. Admitting that part from the rest for the position indicated in the figure along a path contained in a vertical plane. Get the value of the angular coordinate at the instant...

Homework Statement If the speed of a roller coaster at the bottom of the loop is 25 m/s, what is the normal force exerted by the car by the track in terms of the car's weight mg? Homework Equations N - mg =mv^2/r The Attempt at a Solution N=mv^2/r + mg N=m(v^2/r+ g) N=m (31.25...

Homework Statement :[/B] A girl pushes a 24 kg lawn mower as show in the figure. (figure shows a girl pushing a manual push mower. The force is going down the handle and theta is from the ground to the mower.) Force=25N and theta=34 degrees. Ignore friction. Gravity does apply at 9.8 m/s^2...