Impact Definition and 911 Threads

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...

Please if we charge battery with high voltage like the battery charge voltage 4.2v and we supply 5v, is that will reduce the battery life. Thank you

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...

Hello! If a person hear song continuously for 15 hours every day for one year by head-phone then will there be any effect on his/her brain?

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...

Can bringing a surplus of Helium 3 from a Extraterrestrial source effect our Earth's ecological balance? Has there been any studies on this?

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?

As in the subject. I have created tri mesh on my solid and it is completely irregular. Does it have any impact on later results of the analysis? Can it be repaired somehow? I attached a picture in case you would like to see it. I am working with Marc MSC

HI gurus I have found helped on this forum, that I am trying again. I would like to know the steps I should follow in other to find the following I would like to find out how fast a car was going before impact, if after a T collision one of the car steer right and stop at 8 Meters...

Velocity ratio is defined as the ratio of the distance moved by effort and load, in the same time interval. It is said and known : that in the first order of lever, velocity ratio is usually greater than 1 but could be less or equal to 1. Why do we say that? And what does it mean? In the...

This is going to sound odd but I am hoping to use physics to defend an allegation made by my ex-wife. She alleges that I threw a knife into my kitchen sink and it bounced up and stuck into the ceiling (in reality I was overseas when the knife was broken by her brother - I'm just hoping to use as...

Homework Statement We recently did an experiment involving the impact of fluid jet on both plane and cupped surfaces. See the diagram attached for the experimental set up. We were asked to 1) verify the conservation of momentum and 2) calculate the discharge coefficient of the nozzle from...

If you are given a ratio, say apples to eggs and you were to increase the number of eggs but keep the number of apples the same, would you say that the ratio of apples to eggs is reduced, as when you divided apples by eggs, the number would be smaller if eggs are increased and apples remain...

Hey everyone, I'm interested in people's opinions about Impact Factors and how useful they are in ranking scientific journals. For extra information I've made an infographic about the top physics journals as measured by Thomson Reuters in their journal citation reports and it's accessible here...

A moving car crashes with a tree. Will the impact force on the car by the tree equal to the impact force on the tree by the car? Does Newton's third law apply here?

How does our body absorb the force from falling? And if we roll or bend our knees while landing why is the force felt by our body less? Can somebody explain?