Impact Definition and 911 Threads

Homework Statement I'm doing a catapult project and I have to calculate a few pieces of information. The initial velocity of the release (horizontal and vertical components) , the time of the highest point, and velocity of impact of the object. I know how to do all of these except find...

first of all I have a case that is screwed in another case ,I like to know a basic way to calculate the impact force in the screws ,the are 16 screws, I try using the basic impact force formula and the conservation of energy in the free fall,but I am having problems since I don't have the D...

I am trying to model the following situation: Let say i have an obstacle with known mass, and I know the coefficient of static and dynamic friction between the obstacle material and the floor. A car traveling at a fixed velocity is to impact the obstacle. For simplicity i will first consider...

what is a the difference between a static and a dynamic impact?

1. Show that the gravitational force between two planets is quadrupled if the masses of both planets are doubled but the distance between them stays the same. 2. F = G m1m2/d2 ?? 3. confused...

Hypothetically: If a hollow sphere with a human inside were placed exactly at the centre of the Earth's core; then how would gravity affect the human (or any mass for that matter).

We know that we, as humans, with our free will, can alter/impact our earthly world, and to some extent, our solar system. How much **possibly** we can impact/alter our part of the galaxy and/or universe? Is there any role for free will in the continuity of the universe? Just wondering if there...

If an infinitely large rock is traveling infinitesimally slow along a straight line and an infinitesimally small rock is traveling infinitely fast towards the infinitely large rock along the same axis, is the collision elastic?

Hi, this thought came to my mind..not sure how correct this is. In extreme gravity, the space curves. Will the value of Pi change in this case, for a circle near such gravity ? pi = circumference/diameter.

A golfer drives a ball with initial angle θ = 45 from a tee at the origin. The ball hits a window at height h = 10m a distance D = 80m away. a. Find the initial launch speed v0 of the ball. b. Suppose a second golfer tees off from the same spot at an unknown angle and speed, and...

I need help in these two problems. 1. Fernando Jose hits a 0.05 kg golf ball, giving it a speed of 65 km/s. What impulse does he impact to the ball? 2. Automobile companies often test the safety of cars by putting them through crash test to observe the integrity of passenger's...

Would a ball dropped vs launched(horizontally) have the same force of impact? (same starting height) I can't wrap my mind around this... I know there's no acceleration in the x-direction, yet I would imagine the launched object would have a greater force of impact. (negating the ball rolling...

"Blended metal" bullets; much heat after impact? Can anyone tell me? These bullets supposedly will penetrate body armor, but not drywall, and are alleged to pretty well explode when going through flesh. I've read a report by a contractor who used one in Iraq and said the soft tissue damage...

Trying to calculate this for work. Have 160,000 lbs drop 45 ft with mud weight of 16.5

let me explain i do a static tensile test and get the stress strain graph. the area under the graph is the toughness that means i can use this static toughness data to predict the failure under impact loads other idea is that i have done a impact toughess test. if i can get the...

Hello, the professor supervising my bachelor thesis is happy with the results. Together with another co-author, he is currently writing a paper for Physical Review Letters and is considering adding my results to it. However, for this purpose, he needs more general results. In other words, if...

We observe farther galaxies with higher redshifts. How can we be sure that this is due space itself expanding? How do we know that this is not just Doppler shift of galaxies running away from us at higher speeds long time ago, that got lowered (decelerated by gravity of matter in the...

Homework Statement Hello! I have a problem to calculate the equations of impact (not elastic) of a chain of links. The goal is to have joint velocities of the links after impact. I know how to do this without a dependent variabele, see my attempt in...

Homework Statement Two oppositely charged balls are hung by strings from a wooden dowel. The two balls are separated by a distance of R. a) If the balls are moved along the dowel until their separation is 3/2 R, has their potential energy increased or decreased? b) What is the...

Homework Statement Problematic Part of the problem: Consider a negative ion beam of He- ions. The given beam characteristics are the beam energy (E) and the beam current (I). An electrostatic chopper is placed on the beam line, which pulses the DC beam with a pulse width of say t_1...

Hi I was just wondering if anyone could please help me, I was just wondering what would happen to the supply curve if; 1. There was a recession. 2. And if oil prices increases. what would cause the supply curve to shift? thanks heaps for your help Mel

when approaching C the mass of your craft increases. If the mass of your fuel increases also wouldn't that mean the faster you go the more fuel youll have?

Science is not immune to fads. Fads are strengthened by media and institutions entrenching details and hindering objectivity. Examples of what I would consider fad science are, global warming, string theory, quantum realities, a tone of stuff related to nutrition, dieting and health.

Homework Statement A ball is thrown at a velocity of 10 m/s, at an angle of 30° from horizontal and released 2 m above the ground. What will the magnitude of ball’s resultant velocity be at the moment of impact with the ground? Homework Equations Vf2 = vi2 + 2as The Attempt at a...

The month long debacle over the BP oil spill, and earlier collapse of a coal mine killing scores of coal miners, makes me wonder: what are the risk to human safety and environmental impact for mining, processing nuclear fuel (i.e uranium, thorium) ? Could acquiring nuclear fuel lead to a...

Remember those executive toys that were popular in the '80s? You have a steel ball on the end of a thin rod hitting another steel ball that is stationary. As near as we can see, the target ball gets all the momentum of the moving ball, and the moving ball stops dead - close to 100% transfer. But...

So I checked out the physics class I was taking on ratemyprofessor.com and John Ross was the guy who was teaching it. He had good reviews, so I figured I'll take his class. Well, a TA is teaching it, and I won't name the person, but he isn't really a teacher--even with his PhD in astrophysics...

Homework Statement A 4-kg projectile travels with a horizontal velocity of 600 m/s before it explodes and breaks into two fragments A and B of mass 1.5 kg and 2.5 kg, respectively. If the fragments travel along the parabolic trajectories shown, determine the magnitude of velocity of each...

Why?? Why does the time affect velocity in this case not force (as in first case)? Thanks

Homework Statement This is an output of a c program example given by my professor. I have written a program that makes it as far as calculating everything but impact. I have all equations figured out except for how the time of impact was calculated. Enter initial magnitude (0 to 250...

I have wondered how vulnerable is the Space Shuttle to an impact by a small meteor. If a golf ball sized or even a marble sized meteor struck the shuttle, isn't there a very strong possibility of puncturing the shuttle? Would a small hole in the shuttle be catastrophic, causing all the air to...

Hi there, For my Final Year Project at University I am analysing Road Restraint Systems/Safety Barriers in a Finite Element Analysis package. My problem is calculating the force exerted onto the barrier by a vehicle during a collision, more specifically the time over which this impact...

Trying to calculate the impact of an 8000 lb. truck moving at a rate of 55mph, hitting a 200 lb deer that is standing still in the middle of the road. Does assuming it is a localized hit make any difference? What i mean is, if the deer was hit from the back, and his 200lb wieght was focused in...

I'm sure I'm not thinking of this the right way. I'm hoping someone can see the error in my logic. Should a force have less of an impact on a moving object than one which is at rest? An object which is in motion has a momentum given by p=mv. A force F acting (say in the opposite...

probably a dumb question but could a comet or asteroid impact ever create a mini wormhole or mini black hole or the like? also what's worse in terms of impact damage? - a comet, asteroid or meteor? thanks

How do free electrons (metals) impact reflectivity. Why are they more reflective than another surface without free electrons (valence). Does this mean that a medium with no valence electrons will be 100% non reflective. Thanks

Hi, I am currently studying Microeconomics and am a little stuck on a question. It is in relation to a 'consumer subsidy' provided by the government, my textbook does not cover it and I have been unsuccessful locating anything online as it all seems to be about a producers subsidy; which our...

A derivation of the capacitance for a parallel plate capacitor is as follows: [ assume uniform field, plate area is infinite in relation to the separation, the conductors are perfect conductors ] So, V=Ed where V=voltage difference between plates E= electric field (uniform)...

mobile "lights" I have seen some light making stickers sold that can be put on your mobile and they emit light when you talk. Am I right that they will lower my chances of getting connected when I am far from the antenna? I mean they must somehow make signal weaker, don;t they?

1. An asteroid of 1.0 km diameter will make a crater of about 10 km diameter. How much kinetic energy does the asteroid have if it strikes the surface at about 20km/s. Convert answers to megatons of TNT; 1 megaton = 4 X 10^15 Joules. 2. I do not understand how there is enough...

Homework Statement A Bullet of ice at a temperature of 0 degrees celieus is fired into a target Assuming that all the impact energy is retained by the ice what impact velocity is needed to melt 68% of the ice Homework Equations 1/2mv^2 Q = ml The Attempt at a Solution i got.. v^2 =...

I am trying to run a finite element analysis for a collision impact. The program I am using is MD Patran/Nastran. My model consists of moving object colliding with a stationary object. I have created the mesh, applied the appropriate material, applied the boundary conditions (fixed for the...

I'm in a second year physics course, and were studying Rutherford scattering. I'm not having any trouble with the physical or mathematical concepts, I'd just like a more precise definition of the phrase "impact parameter". I searched google, and my notes and textbook but couldn't really find...

Could it be that we are keeping all pets in their baby/infant state, psychologically? Hypothetically, if talking apes were capturing human babies and keeping them as pets (as in Planet of Apes) like we keep cats as pets, the apes would neuter/spay the human children, feed them corn &...

Homework Statement Object is moving directly toward earth initial V = 2000 m/s distance from center of Earth = 8 X 10^{7} m Determine speed at impact Homework Equations g = \frac{GM}{R^{2}} The Attempt at a Solution I am guessing I'll need to integrate to get velocity, but am not...

So a friend and I started a debate over dinner, and no-one around here really wants to side with either of us, since neither of us has any concrete facts on the issue. The issue is this: Which would have a greater chance of causing a fatal impact on someone, a wooden bat or an aluminum bat...

I recently received a speeding ticket for "allegedly" driving my scooter (Piaggio MP3 500) 72Mph on a stretch of road with a lower speed limit. I was traveling too fast and I deserve to pay a penalty; however, I am also hoping the judge will recognize that a speeding scooter is less potentially...

Homework Statement After falling from rest at a height of 29.8 m, a 0.422 kg ball rebounds upward, reaching a height of 21.7 m. If the contact between ball and ground lasted 1.83 ms, what average force was exerted on the ball? Homework Equations Change in momentum (p) = Fnet* Change in...

Homework Statement I've seen this problem on here only twice, once never answered, and the other just saying the OP's "solution" was on the right track Problem: You are arguing over a cell phone while trailing an unmarked police car by 37 m. Both your car and the police car are...

Homework Statement A prince trapped in a castle wraps a message around a rock and throws it from the top wall with an initial velocity of 12 m/s [42 deg above the horizontal] the rock lands just on the far side of the castles moat at a level 9.5m below the initial level. determine the rocks...