Impact Definition and 911 Threads

I just want to check if my thinking is reasonable. Since B,C and D are all dependent or fixed by the oscillator, A is the only factor to affect the amplitude of the motion at resonance or even throughout the entire process?

https://www.plasmaphysics.org.uk/collision2d.htm This is the only one I found, but when I plug in the numbers of his example I get a wrong result. Do you know any others who solved it i.e. considering the angle of impact? Angle of impact I name the angle that is shaped between the initial dx...

Summary:: What is the temperature change of a bullet upon impact. I have this problem to solve but I'm kinda stuck, would apricate any feedback. We fire a silver bullet with a muzzle speed of 200 ms−1 into a sack of sand. What is the temperature change of the bullet, if 40 % of its kinetic...

A short primer for the topic can be found here: https://econ243.academic.wlu.edu/2017/04/07/disruptive-deflationary-technology/ Mainly the gist of the issue has to do with technology such as, cell phones, the internet, artificial intelligence, automated services, increasing efficiency and...

Hi, how can I calculate the impact force in case when some object is in uniform circular motion and then suddenly hits the target. For example consider lawn mower's blade hitting stone or drum woodchipper's blade hitting branch. Both blades are already moving at full speed when they hit the...

Hello everyone, happy holidays! Y/day i googled that question (see title), and i found no clear answer, and I was really suprised, So I had to investigate my self, this is a super basic question, Let me know if i got this right: Earth R: 6,371 km Moon R: 1,737.1 km d1: 384,400 km (center to...

If the Hadley cell, which goes all the way around Earth, causes the the Sahara, surely the desert zone should likewise go all the way around the Earth, and there should be a mirror image of it in the Southern Hemisphere, shouldn't there?

Hi. I'm a physician trying to understand the micromechanics of lung injury due to overdistension. The basic idea is that overstretching of the plasma membrane of the lung epithelial cell causes "stress failure" --> i.e. plasma membrane rupture --> cell death. The concepts of stress, strain, and...

Hi everyone, I'm a police dog trainer and am trying to explain to people at demos the impact of a police dog on a helper wearing a body bite suit at impact. So, a 75 pound German Shepherd traveling 28 mph for 60 yards impacting a 185 pound person in a body bite suit. I'm trying to determine the...

So what I know is that without the edition of the R5 resistor R2 and R3 are 0 because the capacitor is short circuiting them. Why does the addition of the R5 resistor cause R2 and R3 to be calculated into the Req for the current equation?

Why does Hollywood think that kids want to watch kids on television or movies? I preferred watching my TV heroes, Flash Gordon (Steve Holland), Superman (truth, justice and the American way, lol it used to actually be true back then) and Tarzan. And I certainly don’t enjoy watching children most...

Hi, Hope this is the correct forum for this kind of question. I am doing an explicit finite elements simulation of a tank, weighs around 7.5 Kg with internal parts, falls from 1 meter. Since I never had a validation of such an experiment I am trying to understand if the numbers are right. I...

We know that SARS-CoV-1 affected the world in 2002-04. Many countries including China were affected then. I want to know, how the SARS-CoV-2 is faring now, in the areas which had already been affected by SARS-CoV-1 earlier. Dr. Beda M Stadler the former director of the Institute for Immunology...

I've learned that the surfaces of places like the moon and the surfaces on Mars corresponding to the Noachian period signify relatively old surfaces because weathering and erosion tend to make those cratered surfaces smooth. However, I heard a professor mention that this is also true for icy...

Why does PRL have such a small impact factor? There are so many great papers published there (if I am not wrong the Higgs discovery, too?), how do they define the impact factor of a journal?

I believe momentum conservation is to be used in this sum since there's no external force, but I am not sure how to write the equation. Can someone please help me out:)

Hello Can someone please tell me what is the use of poisson's ration in determinig stress cos what I know in this case we should have stress=E*strain and so now use for poison

Hi everyone! I wanted to pose this question to all of you and ask you what impact the current COVID-19 pandemic has had on your job. In my personal case, the impact has been fairly minimal. As a biostatistician for a consulting firm for the pharmaceutical industry (and who has been working from...

I've been reading about faraday cages. The way I see, it works because the condutor will separate the charges so that the eletric charge inside is 0. Then I saw a lecture in which the professor was carrying a radio and the signal stopped as soon as he entered the cage however we were still able...

I apologize in advance if this is in the wrong forum, I have no idea where this question would really sit. A number of proposed theoretical weapons, and a concept often used in science fiction, describe a satellite launched, or rather dropped, rod that would gain large amounts of kinetic energy...

Through the research that I conducted is that I wasn't able to find actual supporting answer to this question. I struggle with Physics and math and because of Coronavirus my school has shut down meaning I don't have access to my teachers or tutor. The main line that i am thinking is that if it...

Hi all, I have just started work experience at an engineering company in the design department. I've be tasked to develop a test rig, Similar to a charpy rig. Intended to measure the impact strength of materials. The design will consist of an A-frame structure with swing arm attached to the...

Hello Physics Forums, I enjoy playing pool, my knowledge of physics is almost nonexistent, so I apologize in advance for my ignorance. In a nutshell, I would like to understand how the hardness of a pool tip effects energy transfer in that brief moment of impact when a pool cue tip hits the...

The Yarrabubba impact structure in Australia was known to be old, but until now no precise date was available. Researchers have determined its age as 2229 +/- 5 Ma, which makes it the oldest yet recognised. The authors of the paper note that "While the Yarrabubba structure . . . . represents...

Summary:: <mentor moved to general discussion> I mean of the discovery of the Graviton or of any other unification theory that would explain gravity and would be compatible with quantum mechanics. And by impact I don't necessarily mean just the understanding of the world - this is implicit -...

I saw this as part of Science Magazine's Breakthroughs of the Year: https://vis.sciencemag.org/breakthrough2019/finalists/#A-killer based on this study in PNAS (possibly paywalled): https://www.pnas.org/content/116/39/19342 I had missed the paper when it first came out, and a quick skim of this...

Hello all I was hoping someone could help with understanding how fluids level out under atmospheric pressure. For example:- Below is a picture of a tank of water with a closed door at the bottom, the door leads to an inclined pipe that is closed off at the end there is another pipe connected...

Hi there, First of all i want to apologize for my english, but i am not from english speaking country, so i am not perfect in it. Now for the question. I need to calculate instantaneous impact force in the lower dead center of Charpy hammer knowing nominal potential energy in lower dead center...

I have an assignment and i want to complete it before Tuesday. I have some questions regards to my assignment 1) How Engineering physics impact on technology ? 2) Engineering physics Inventions 3) Engineering physics related information

When ICs undergo accelerated testing via thermal cycling, wouldn't rate of temperature increase factor into the equation? For example, in Equation 4 in this pdf: http://www.issi.com/WW/pdf/semiconductor-reliability.pdf The Temp Cycling Acceleration Factor is a function of Tmax,stress and...

Suppose a bullet with high speed strike a wooden block and move together after collision. We know there is loss in total KE of bullet-wooden block system. The question is, if the part of the loss in KE of the bullet is transfer to heat energy, HOW to prove the CONSERVATION of ENERGY in this...

So I am trying to answer a question which is about an egg toss game where two people try to throw an egg at each other without breaking it.The question is how can the force of impact be reduced so that the egg doesn't break. With respect to the F = Δ p / Δ t formula, I think increasing time of...

This is a serious question, and it is not meant as an attempt to "debunk" greenhouse warming of the earth. Wikipedia has the below image, which shows the atmospheric transmittance as a function of wavelength. Notice the red vertical line through one of the CO2 absorption bands. We see that the...

This NY Times article discusses findings based on iostopes of Boron in ocean sediments that indicate a geologically instant acidification of the oceans following the Chicxulub impact. The Daccan traps (resulting from an eruption of over 200,000 cubic miles of lava in about a million years)...

Hi, I am a bit out of my league here, but had a question. I have 5 pieces of .25" thick foam/padding of different densities, and I wanted to measure which one absorbs the most energy (weakens the impact) when struck by a fist/punch or even a ball, how would I do that? I ran across a...

Here were my assumptions: Energy and angular momentum are both conserved because the only force acting here is a central force. The initial angular momentum of this particle is ##L = mv_0b## and we can treat E as a constant in the homework equation given above. I solved for the KE (1/2 mv^2) in...

Generic biomass such as leaves contain a large amount of total carbohydrates, mostly in the form of cellulose. Some animals such as apes and can digest cellulose and that is how they can survive on leaves. Humans cannot digest cellulose because we lack the enzymes necessary to decompose...

1. Which organization or group of organizations is it the responsibility of to detect and track worrisome asteroids? I believe NASA and the USAF track such bodies if I'm not mistaken, but how many others are there? Who is "best" at it, or most relied-upon for spotting and cataloging them? 2...

Does the real vacuum pressure/underpressure depends only on the amount of impurities? In the case of theoretical Torricelli vacuum test, when no purities left in the vacuum: Is the vacuum 0Pa at 1m height (with 760mm of Hg) and also the same at 10m height (also with 760mm of Hg) of the test...

I've been wondering this for a while. It's usually noisy in my day to day environment so I usually play music in my earphones to help me concentrate, sometimes for hours. Would there be any negative effects to this besides loss of hearing? I feel as if music may overstimulate the brain though I...

Summary: Hi, I'm doing an assessment for Physics on Optics topics, but I can't really explain how the CV affect the RV CV : Focal length of convex lens RV : Temperature of water after 20 minutes under the sun How I should explain for the temperature difference? 🤔 Please help, Thanks.

If I have impact test data showing energy absorbed by notched specimen, how do I utilize this data while designing. In my case, i am trying to design the valve which closes by striking on valve seat, how do i use the impact test results for this design?

I have the calculation on secret key rate over the turbulence channel using Python code. The calculation is as below: import numpy as np import math import re import random import cmath #import itertools from math import pi,e,log import time #import xlwt import matplotlib.pyplot as plt from...

Hi all, I'm a bit embarrassed but I'm extremely rusty with a lot of engineering principles. I've mainly been working in automation and controls within a manufacturing setting and have not done anything like this in ages. Anyways, I have a problem I need to solve and I need to determine the...

Now, the net vertical impulse on the wedge should be zero. It's quite obvious from the figure that the ground will also exert an impulse of ##J cos 30°## on the wedge. But they've given the answer as ##J sin 30°##. They're wrong, right?

I am new to Simulink and I wanted to start practicing using a spring mass damper system. My first tutorial was this: Later, I wanted to model a spring system where a mass moving at a known velocity hits the spring. The governing equation and a similar modeling method given in the previous...

Can the electron-electron interaction have an impact on the conductivity? Google seems to point out that yes for some 2d materials such as graphene. But what about 3d materials? Intuitively, any lost momentum by an electron would be gained by another electron, so in average, this e-e...

I am in a process of making a mathematical model of an automobile driveline validation procedure called "Driveline impact". In this test, after the engine in cranked, first gear is selected. While clutch pedal is still pressed, engine rpm is raised unto its max. torque deliverable speed. In this...

See Peter Shor's comments here and here and Urs Schreiber's comments here.

Bolt comes out by distance d=1.58 mm when speed of rotation of shaft reaches its trip value (w_trip). m is mass of trip weight (Bolt assembly) One of the approach which I had considered is work energy theorem. Initial energy = 0.5m*(w_trip*(r+d))^2 Final Energy= 0.5m*(w_trip*r)^2 (Assuming bolt...