Say you are interviewing for a tenure-track position...you've got a PhD and a postdoc or two under your belt in your field of specialization. Would the specific courses that you took (or did not take) in grad school have a large effect on the hiring decision? Especially if there is a course...
I'm designing a tool that will be driven by an impacting peening gun. The peening gun will be act like a jack hammer with a flat tipped cylindrical anvil. The tool being hit will have a steel insert that will act to transfer the energy from the impacting peening anvil to the tool. I've done...
Earth is changing constantly and there is still so much we don't know about it.
Researchers construct a model of impact for El Nino / La Nina events
17 hours ago by https://sciencex.com/authors/bobyirka/
Phys.org) —A small team made up of researchers from the U.S. and Europe has constructed a...
Homework Statement
Once a circular path has been obtain for the electrons, how will increasing current to the coils affect that path? Use equation 1 and the fact that e/m is a constant for the electron.
Homework Equations
e/m = 2V/B^2r^2
The Attempt at a Solution
I'm unclear as to how to...
Homework Statement
A student stands at the edge of a cliff and throws a stone horizontally over the edge with a speed of 16.0 m/s. The cliff is h= 41.0 m above a flat horizontal beach
h=41
g=10m/s
vi=0m/s
vf2=vi2+2gh
vi=28.64
h=vi+vf/2xt
41=28.64/2xt
14.32
t=2.86
28.64x28.64, 16x16
Square...
Homework Statement
A ball is thrown toward a cliff of height h with a speed of 28.0 m/s and an angle of 60.0° above horizontal.
What is the ball's impact speed
Homework Equations
Vf=Vi-at
Sf=Si+Vit-1/2gt^2
Vy=sintheta
Vx=costheta
The Attempt at a Solution
first find the vertical velocity =...
Homework Statement
What would be the effect of calculated value if:
a. Jockey weight is in error by 1 g?
b. Distance from vane center to pivot point is in error by 1 mm?
c. diameter of nozzle 0.1mm different from actual nozzle diameter.
Homework EquationsThe Attempt at a Solution
as the error...
Hi! I have apparently forgotten way too much college physics, and could really use some help here. I'm trying to calculate the impact force of an instrument (a Schmidt hammer--uses a spring-loaded piston) that produces an impulse against a surface. The instrument registers a rebound value (which...
So I've been becoming pretty obsessed with base jumpers. However its a pretty dangerous sport and as it turns out (surprise) a lot of them die. I was just wondering how much force the human body can survive. Say a 90kg base jumper jumped off of a 900m mountain and their parachute failed to open...
Hello everyone!
I happen to read this forum a lot, but I've never posted/became a member since I didn't have a specific question that wasn't already asked before or because I did not feel I had anything relatively original to contribute. So, I have a question to which I cannot seem to find an...
Homework Statement
A ball is thrown from a bridge 200 m high with an initial velocity of 34.4 m/s at an angle of 54° above the horizontal.
Homework Equations
I'm not sure... arctan Vx/Vy = x? I really don't know.
The Attempt at a Solution
(a) How high above the throwing height does...
The problem comes up as part of a final master's project in FEM analysis. The project consists in calculating the oscillation response of the World Trade Center towers after the plane impacts. The particular problem I'm having trouble is that I need to transform the plane impact of which mass...
I was reading Cengel's thermodynamics and noticed that he uses a thought experiment to show that there is no machine that is more efficient than the Carnot reversible machine. He says that both a reversible machine and an irreversible machine are connected to high and low temperature deposits...
Hello, i am not an expert in physics (i am a computer scientist) but i have a lot of interest in physics, still there are some questions that i can't seem to answer given my limited amount of knowledge in physics (i had only 1 classical mechanics subject in university, although i try to learn a...
I am very interest in knowing about how skin reduced force that can damage bone.
I guess it act like a protective layer by flexing and stretching such as a trampoline. Also skin redistribute the force and spread out evenly and the soft tissue play role here too. Please help if someone have any...
All,
I need your help, please...this is true
I was rear ended and I would like to know the impact force...
I was waiting for the car in front of me to turn left, so I had my foot on my brake, I was driving a 2004 Lexus RX330...call it 3500 lbs.
A large truck was texting and...
Hello All,
Some background information: I'm a co-op engineering student and recently my supervisor asked me to do a bit of research on a solution to a problem we had. Essentially, a cardan shaft connecting a motor and a gear box failed at a joint during operation and caused some extensive...
Homework Statement
A ball A hits another ball B 3 times more massive and rebounds at an angle λ = 43°.1... (cosλ =5/√52).
Can anyone determine the angle of impact? is it possible , at all?
Let \lambda be a linear density of a rope which is moving into a scale at velocity v. The additional force on the scale due to the collision is given as
\frac{d p}{d t} = v\frac{d m}{d t} = \lambda v^2
Where as the stagnation pressure from stopping a column of water in excess of static...
Hello,
Been a while since I posted on here, nice to be back :) .
I just want some pointers as to the methodology for an impact load case that I'm looking at. I've attached a very basic sketch of a trolley which is traveling at a known velocity and impacts a rigid structure at it's base.
What...
I had a professor for a real analysis class that I really enjoyed. I was curious about his research. I asked him to do a senior thesis and in doing so, he introduced me to area of math/physics that I love (stochastic dynamics, as applied to quantum/stat mech). It was an amazing experience...
Hi All,
I am trying to determine the correct equations to apply with a problem I have run into at work.
Basically I have a shaft with a cutter with straight flutes, I am trying to find out the torque load on the shaft when the cutter flutes make contact with the material they are cutting...
Okay, say we have an electric fan that is used as a compressor, and behind that is the main burner, and behind that is a constricting divergent-divergent nozzle. Say that the pressure and temperature behind the compressor is such that it is choked, meaning the mass rate cannot be increased. Now...
How accurate do you think are the assessments made by students on this website??I had nothing but good things to say about all my professors. When I started in community college last year I joined late and had to take the professors whose classes were available. I did not even bother to check...
I really want to know if there is a difference between the force from the first impact of water and the force from water resistance. If it is different can someone tell me a explanation on why it is different?
Example:
I am not quite good at physics and would like some help
Thanks!
Hi, I was studying the impact of electronegativity in a row of the periodic table on the acidity of compounds.
I came upon a problem of definition: what exactly is a compound? Does it have to be electrically neutral AT ALL TIMES?
Hi there,
I have a question here:
"An asteroid is measured to have a speed relative to the Earth of 15 km/s while it is still far away. What is the speed of impact of the asteroid with the Earth?"
I'm stumped. I don't even know where to start with this one -- it doesn't talk about how...
Homework Statement
Two horizontal bars connected by a frictionless pin are released and allowed to fall and impact a fixed pin. Where must the pin impact the bars to ensure rigid body rotation?
Homework Equations
Conservation of angular and linear momentum, relative velocity...
I am interested to know if there is possible to find out the contact time by a colliding object into a plate, given material properties? My object is to find out the pressure on a plate using force acting on an area.
What i know:
Mass of both projectile and target plate
Impact velocity...
Impact of magnetic field on a "dirty" plasma.
This follows on from an earlier post of mine, which is now closed. I can also now disclose that it refers to my UK Patent Application GB1312183.5, which claims (in essence) that a linear motor can be used as a compressor for a jet engine.
That...
Hello Guys,
I have been doing Charpy tests for the past couple of months and notice that I can't get rid of the water that keeps freezing and sinking to the bottom of the my chiller. It's becoming more of a hassle that my agitator stops due to the water freezing at the bottom of the chiller...
Homework Statement
I just did a lab on inelastic collisions and this was one of the discussion questions:
Consider a situation in which you are the driver of a car stopped at a red light and you see a car of similar mass approaching rapidly from behind. Use the results of your experiment...
Homework Statement
Q: "Two meteoroids are heading for earth. Their speeds as they cross the moons orbit are 1km/s.
The first meteoroid is heading straight for earth, what is it's speed of impact?"
Velocity = 1km/s
Rearth = 6.37E6 m
Dmoon = 3.84E8 m
G = 6.673E-11 N*m^2/kg^2Homework Equations
E...
I am currently working on an experiment with piezoelectricity and was wondering how I would measure the force applied to the crystal. I have been tapping the crystal with a screw driver and was wondering how I would calculate the force of these taps as I cannot find the amount of displacement in...
I am designing a surgical instrument which will be impacted many times over its life cycle. We are trying to determine the best heat treating option for the steel (17-4 precipitation hardened) so that we maximize its usable life. Typically, we heat treat 17-4 to H900. However, I'm not sure...
Impact and collision -- having problems
A smooth sphere A impinges obliquely with an identical smooth sphere B which is at rest. the direction of A before and after impact makes angles 60 and X , respectively, with the line of centres at impact. the coefficient of restitution is e.
prove that...
I read in a science magazine that you would be able to generate more energy by collecting a mass of water and tipping it through a turbine than from generating energy from the impact of that mass of water as individual raindrops. Now this may simply be to do with the technology we have that...
My 12 year old daughter is conducting an experiment that includes testing various sporting helmets to determine which will protect your head best from a concussion. She is planning on dropping a 10 pound weight (approximate weight of human head) onto each side of the helmet. How can she...
[b]1. Encountered with cue to a massive billiards ball, which is initially at rest, see figure uploaded. The ball has radius R and mass M. The queue hits with force F horizontally into the bale height h above the table, and the shock lasts a very short time Δt.
It is reported that the moment of...
If we neglect the effects of air resistance, the impact speed of a body of mass m released from rest at an altitude of 2 x 10^8 m above the surface of Earth (mass of Earth = M = 5.99 x 10^24 kg, radius of Earth = 6.37 x 10^6 m)
It's a multiple choice and I think I have it, but I just want to...
I have been struggling with this problem. I'll greatly appreciate someone pointing me in the right direction. I think it's safe to assume the velocity of the impact is the Earth's escape velocity 11.1*10^3 m/s
Here's the problem:
Impacting objects will excavate a certain amount of debris...
Car A was turning right
Car B was stopped at stop light.
Car B with no further oncoming traffic at the time proceeded across the intersection. Halfway across the intersection Car C T-bones Car B.
CAR B is 2012 Chevy Silverado 4X4 LTZ
CAR C is approx 2002 Nissan Sentra (I believe)
When Car...
Homework Statement
Ok, so in a lab I was preforming Izod impact tests on notched polymer specimens.
To complete my calculations I need to determine the correct cross-sectional area to use (Which is baffling me as the simple things usually do)
The sample was loaded with the notch facing...
Homework Statement
1200kg car moving at 9.72m/s runs into and sticks to a parked 1000kg car. The collision takes 0.15s and after the crash the cars wheels lock and they skid to a stop on u=0.40 road. What is the impact force on both cars?
Homework Equations
J=F*t=m*dv
The Attempt at a...
Hi folks -- could anyone think of a justification of the idea that if a function's arguments diverge (i.e. are taken to infinity), there's a high probability that the function too will diverge?
This would be really helpful for thinking about fundamental theories in particle physics, so any...
Can someone please give me a bit of advise. I was dealing with impact toughness of materials today, which I haven't dealt with since uni days. I was involved in charpy testing. I understand the concept of finding the impact toughness from the test [ m x g x (h2 - h1) ].
But what I can't get my...
What would be the foreseeable impacts on science if it were possible to solve the Schrodinger or even Dirac equations analytically (and exactly) for every case?