What is Applied force: Definition and 127 Discussions
In lithic analysis, a subdivision of archaeology, a bulb of applied force (also known as a bulb of percussion or simply bulb of force) is a defining characteristic of a lithic flake. Bulb of applied force was first correctly described by Sir John Evans, the cofounder of prehistoric archeology. However, bulb of percussion was coined scientifically by W.J. Sollas. When a flake is detached from its parent core, a portion of the Hertzian cone of force caused by the detachment blow is detached with it, leaving a distinctive bulb on the flake and a corresponding flake scar on the core. In the case of a unidirectional core, the bulb of applied force is produced by an initiated crack formed at the point of contact, which begins producing the Hertzian cone. The outward pressure increases causing the crack to curve away from the core and the bulb formation. The bulb of applied force forms below the striking platform as a slight bulge. If the flake is completely crushed the bulb will not be visible. Bulbs of applied force may be distinctive, moderate, or diffuse, depending upon the force of the blow used to detach the flake, and upon the type of material used as a fabricator. The bulb of applied force can indicate the mass or density of the tool used in the application of the force. The bulb may also be an indication of the angle of the force. This information is helpful to archaeologists in understanding and recreating the process of flintknapping. Generally, the harder the material used as a fabricator, the more distinctive the bulb of applied force. Soft hammer percussion has a low diffuse bulb while hard hammer percussion usually leaves a more distinct and noticeable bulb of applied force. Pressure flake also allowed for diffuse bulbs. The bulb of percussion of a flake or blade is convex and the core has a corresponding concave bulb. The concave bulb on the core is known as the negative bulb of percussion. Bulbs of applied force are not usually present if the flake has been struck off naturally. This allows archaeologists to identify and distinguish natural breakage from human artistry. The three main bulb types are flat or nondescript, normal, and pronounced. A flat or nondescript bulb is poorly defined and does not rise up on the ventral surface. A normal bulb on the ventral side has average height and well-defined. A pronounced bulb rises up on ventral side and is very large.When explained visually, the bulb of percussion is visible on the ventral face as opposed to the dorsal face (where it is smoother) and considered to be on the "inside" of the parent core. The bulb of percussion is the primary feature that identifies the ventral surface of a flake or blade artifact. Locating its position reveals which is the proximal end of an artifact. Along the proximal end there may be the formation of ripple marks. These ripple marks allow for the direction traveled by the applied force through the lithic when it was detached. Typically, the striking of the flake is produced by knapping (or flintknapping), a process in which requires the user to chip away material from high-silica stones like "flint" in a carefully controlled manner with special tools to produce sharp projectile points or tools. A common characteristic that is associated with the bulb of applied force is a bulbar scar. This scar is from a small chip or flake on the bulb. This is known as an eraillure flake scar. It is produced during the initial impact of flake removal. Occasionally, there is more than one contact point on a striking platform which creates a series of superimposed waves. The eraillure flake is a chip removed through contact of a dominant force wave that creates the conchoidal flake and inferior waves. Bulb of applied force is not produced by bipolar technology or wedging initiation.
Consider a spring in its natural length. I start pulling the string and the force i apply increase from 0 to 5, while this happens theres a restoring force wanting to be back in its original position(intermolecular force) and i am able to stretch the string until this spring force or restoring...
Hello! I wanted to make sure I am doing this right. In general for a driven damped harmonic oscillator:
$$\ddot{x}+\gamma\dot{x}+\omega_0^2x=\frac{F}{m}\sin{\omega_dt}$$
where ##\gamma## is the damping, ##\omega_0## is the resonant frequency, ##m## is the mass of the particle, ##F## is the...
If F is applied at an angle above the horizontal, it decreases the normal force and vice versa.
So in case A,
net force along X = F applied cos theta - friction
since the object is moving with constant velocity, a = 0 and so the above equation becomes
F applied cos theta = friction
Now along...
The following passage is from Halliday Resnick Krane in Chapter 3 which is about dynamics in one dimension.
"We can measure frictional forces. By placing the body on a horizontal surface where it experiences a frictional force, we could attach a spring and pull the body with just the right...
-i had begun by finding the normal force =147 N
-then found the force of friction=99.96 N
-found the work of friction=-799.68 J
after that I am unsure of where to go since I don't have a force applied
In my teacher’s notes, it said that when the applied force on an object equals the maximum static frictional force, the object begins to move at constant velocity. My question is if both the applied force and the frictional force cancel as they are equal in magnitude, what force accelerates the...
I calculate in this way as follows and get a correct answer. Howere I am not sure if I am using the right way.
F R = (½ MR^2 + MR^2 ) a/R
F = 3/2 Ma
F - f = Ma
f = 3/2 Ma - Ma = Ma/2
Let ##μ_k## = 0.5
##F_a## = 10 Newtons
##\theta## is the angel of the Applied force.
How will the acceleration of the block change if the angle of the applied force is increase by ##5^o##? Write Increase, Decrease or Stay the same.
Recently we were discussing a question similar to this in...
Homework Statement
We have a yo-yo and the force ##F## which is the tension in the string and this is at the top tangent as shown in the figure attached with this problem. I want to figure out the direction of the friction at the point of contact.
Homework Equations
Newton's laws of motion...
Hi everyone...
I work in a rolling mill that produces train rail tracks. But I'm experiencing some problems. The guards I use keep breaking.
So here is the scinario. The rail we make is 40kg per meter. With a total length of around 65m. When it goes thru the mill pressure is applied to it in...
Homework Statement
A 12.0-kg box is pushed along a horizontal surface by a 24-N force as illustrated in the diagram. The frictional force (kinetic) acting on the object is 6.0 N
A) What is the acceleration of the object
B) Calculate the value of the normal force acting on the object
C) If the...
Homework Statement
How does an applied force and a frictional force compare when moving at constant velocity?
Homework EquationsThe Attempt at a Solution
What's happening Form,
It's been a while since I've done a FBD, but I wanted to get someone's input here and tell me if my math/logic is correct. I want to install a cantilever steel beam with a 20 lb mass at the end of it. I'm using carbon steel ASTM A108 (cheapest steel on McMaster-carr). I...
Homework Statement
what is the angle the force should apply in order to be box number 1 in static position and box number 2 move
Homework Equations
F=ma
The Attempt at a Solution
Homework Statement
A 0.140kg baseball traveling 35.0 m/s strikes the catcher's mitt, which in bringing the ball to rest, recoils backward 11.0cm. What is the average force applied by the ball on the glove
Homework Equations
F=ma; FAB=-FBA
The Attempt at a Solution
Not sure where to start for...
In the image above, a centroid with radius 1 is depicted. F1 is pointing directly at point A (which is the center of the circle), and F2 is pointing directly at point B. The radius for finding the torque would be the perpendicular between the center of the object and the force vector, so r1...
Homework Statement
When an applied force elevated at angle θ is used to drag mass m along a surface with μ as the coefficient of friction, the mass accelerates horizontally with some value, a. Derive the cleanest and most simplified formula for the applied force, Fapplied, that will give the...
Having trouble researching/discovering any locking mechanisms that engage with force in a linear direction and then allow the engagement to be released with force in the same applied direction. I don't know if it has been done, any help/findings would be greatly appreciated. The only technology...
Homework Statement
A 0.145 kg baseball traveling at 35.0 m/s strikes a catcher's mitt which, in bringing the ball to rest, recoils backwards 0.11 m. What was the average force applied by the ball on the glove
Homework Equations
Fnet=ma or F=ma
The Attempt at a Solution
I am honestly so lost...
Homework Statement
A constant force F of magnitude 82.0 N is applied to a 3.00 kg shoe box at angle phi = 53.0°, causing the box to move up a frictionless ramp at constant speed. How much work is done on the box by when the box has moved through vertical distance h = 0.150 m?
Homework...
I think this question is not important and rarely noticed, but I'm still curious XD
kinetic coefficient of friction is used when the applied force of static friction coefficient is less than than the force that we give, or less than or equal to the force that we give?
sry for my bad english
Homework Statement
A horizontal force F is applied to hold a block, mass m = 1.7 kg against a vertical wall. The coefficients of kinetic and static friction between the block and wall are 0.81 and 0.87 respectively. F is gradually reduced until the block falls. Just before it falls, what is the...
Homework Statement
A small textbook is resting on a larger textbook on a horizontal desktop. You apply a horizontal force to the bottom book and both books accelerate together. The top book does not slip on the lower book. What forces causes the top book to accelerate horizontally?
Homework...
Homework Statement
A child is pulling a wagon of mass 7.38 kg up a hill inclined at an angle of 14.3 degrees to the horizontal. The child applies a force parallel to the hill. The acceleration of the wagon is 6.45 cm/s^2 up the hill. Friction is negligible. Determine the magnitude of (a) the...
Homework Statement
If I consider a force, which is applied to both ends of a rectangular beam to its cross section with dimensions w (width) and h (height) and I know the length of the beam is l and the force is parallel, how can I calculate the stress?
Also, what if the force were parallel to...
Something said in my physics textbook really confused me.
The following was written : "Applied Force is our label for a contact force that a person exerts. When an applied force acts at an angle, it is actually a combination of two forces : normal and friction. The component of the applied...
Homework Statement
Two students push horizontally on a large, 65kg trunk. The trunk moves east with an acceleration of 2.0m/s^2. One student pushes with a force of 2.2x10^2 N[E 42 degrees S]. The force of friction acting on the trunk is 1.9x10^2N[W]. Determine the force that the other student...
Homework Statement
This is not a specific problem, but is it true that if you added all of the forces acting on an object except for friction, that the direction of friction would be opposite the direction of that net force(technically, it's the net force except friction)? For example, If you...
Homework Statement
Muscle can be torn apart by a force of 100,000 N applied across an area of 1 m2. A 10 cm2 muscle therefore will be torn by a force of 100 N.
If a student of average size were being lowered into a black hole of 1 solar mass, at about what distance from the hole's center will...
Hi,
I'm wondering what's going on when a friction force of a surface is applied to a moving block as the block slows down to zero and it, the friction force, is the only horizontal force applied. Does the friction force continue at a constant value until the last moment and just drop to 0N or...
Homework Statement
Three boxes are in contact with each other on a frictionless horizontal surface as shown. The masses of the boxes are m1 = 10 kg, m2 = 20 kg, and m3 = 30 kg. A horizontal force F = 90 N is applied to m1.
Calculate:
a. the acceleration of the three boxes.
b. the net force on...
So we are doing a lab in class where you have to calculate coefficient of friction.
This picture shows exactly what we are doing except the wooden block is flat
There weight on the string.
http://facstaff.gpc.edu/~apepper/website pics/friction2.jpg
So
what does added load (there is no...
Homework Statement
A 2000 kg car is driving up a 20° grade at a speed of 85 km/h. What force must be applied to the car to accelerate it up to 100 km/h in 10s?
m= 2000 kg
θ= 20°
Vo= 85 km/hr = 23.6 m/s
Vf = 100 km/hr = 27.8 m/s
t = 10 s
Homework Equations
F = ma (Fx = max)
Fx= Fcosθ
Vox =...
Homework Statement
I'm trying to create a problem for my physics standards that is hard. I gave myself a ball being pushed down a carpeted decline at 24° from the horizontal. The balls starts with an initial velocity of 1 m/s and ends the 6 meter decline at 5 m/s. I want to find the applied...
Homework Statement
An applied force of 30N acts on a 8kg box at an angle of 40 degrees above the horizontal. What is the acceleration of the block if =0.1 and μk = 0.05? What is the acceleration of the block without any friction?
Homework Equations
Equation 1
F k = μ k F N...
I did attempt the problem, but I' now more confused than ever. Please help me.
Joe is moving his refrigerator to take to college and he begins by pushing it across
the wooden kitchen floor.
On a flat surface like the floor, how do you calculate how hard he needs to push?
Draw a free body...
In a closed loop when we apply an applied force on an object the object starts at point A and stops at point A.
Since the displacement is 0, Work done by the applied force on the object is = F x s x cosθ...
i am having some trouble figuring this out
I can not figure out which formula to use i have tried Mass x G x Static Friction
which resulted in 1 x 2 x 9.8 = 19.6
I have a question that has been puzzling me for a while.
When I drive my truck and accelerate hard until 25 mph then put the clutch into roll freely, the truck will climb a few more mph before beginning to slow down. This is on flat ground or even a slight uphill.
The way I see it is as...
This isn't so much homework as it is me having trouble understanding a concept.
I'm having trouble understanding resonance the definition in my book is
"If the frequency of a periodic force applied to a body is the same as or very near to its natural frequency that body will vibrate with...
Homework Statement
A 90 kg box is pushed by a horizontal force F at constant speed up a ramp inclined at 28°, as shown. Determine the magnitude of the applied force.
when the ramp is frictionless.
when the coefficient of kinetic friction is 0.18.
Homework Equations
Ff= uk(Fn)
The...
Homework Statement
10kg block on a inclined plane (32degrees) (frictionless) and an applied force 120N horizontally. What is acceleration?
Homework Equations
Fnet = ma
The Attempt at a Solution
mgsin32 = 51.9N (from mg)
From applied force, in the same plane, we have xcos32=120...
Homework Statement
A light rigid cylinder of radius 2a is able to rotate freely about its axis, which is horizontal. A particle of mass m is fixed to the cylinder at a distance a from the axis and is initially at rest at its lowest point. A light string is wound on the cylinder, and a steady...
Homework Statement
The mass of the two objects on both sides if the pulley is given. So is the acceleration to start moving. It's asking to find the applied force. How do I do that?
Mass of 1- 4.5kg
Mass if 2- 3.0 kg
How much force must u exert to get M1 to accelerate at .25m/s2
Homework...
So I've been stuck on this type of question, please help!
You are pushing horizontally on a 3.0 kg box of wood, pressing against a wall. If the coefficient of static friction is 0.60, how much force must you exert on the block to prevent it from sliding down?
Homework Statement
What is...
Homework Statement
A 900kg car is moving on a level road at 80km/h. If the brakes are applied, what is the distance it will take to stop if the coefficient of kinetic friction between the tires and the road is 0.45.
Homework Equations
F=ma
D=vt
Vf=Vi+at
...
Really basic Kinematics...
I have a 36" OD aluminum drum within another 48" OD aluminum drum creating 6” channel between the two diameters. The total height of the drum assembly is 16” This design project that I am working on requires me to fill this channel up with 12” of water which equates to about 342.5 lbs of water...
Homework Statement
A box with a mass of 22 kg is at rest on a ramp inclined at 45 degrees to the horizontal. The coefficients of friction between the box and the ramp are μs = 0.78 and μk = 0.65
a) Determine magnitude of the largest force that can be applied upward, parallel to the ramp...