Final Definition and 1000 Threads

Homework Statement Find the energy in electron-volts required to remove the remaining electron from a doubly ionized lithium (Li2+) atom. Homework Equations En=-z^2/n^2 The Attempt at a Solution I thought z was 3 for lithium, that doesn't work. I thought since there was only one...

Homework Statement A 2kg. lump of clay traveling at a speed of 20m/s collides with and sticks to a 5kg. lump of clay initially at rest and hanging from a string. Find the final speed of the new lump of clay. How high will the clay swing after the collision? (initial) m1=2kg. v1=20m/s...

Homework Statement The graph below shows the force applied to a 3.8 kg cart initially at rest but free to move on a horizontal track. Calculate the final velocity of the cart, after being subjected to the forces illustrated in the graph. The graph is attached. Homework Equations Okay so I...

Homework Statement An insulated Thermos contains 130 cm3 of hot coffeeat 80.0 degrees C. You put in a 12.0 g ice cube at its meltingpoint to cool the coffee. By how many degrees has your coffeecooled once the ice has melted? Treat the coffee as though it werepure water and neglect energy...

Homework Statement In the 1950’s, an experimental train that had a mass of 22500 kg was powered across a level track by a jet engine that produced a thrust of 4.63 × 105 N for a distance of 533 m. Find the work done on the train. Answer in units of J. Homework Equations The...

I have 4 final exam within 2-3 weeks ( physics, calculus, chemistry and linear algebra). Is this enough time to prepare for all of the upcoming exams? I'm a first year student and would appreciate any advice. Thank you

Homework Statement In an insulated container, .50kg of steam at 140C is mixed with 2.0kg of ice, at -20C. What is the final temp inside the container if heat exchanges with the container are ignored? This is a multiple choice question and the answer is 60C. Homework Equations mC(Tf-Ti) Lf Lv...

Hi, Am new on this forum.I am about to start my final year in electronics and telecommunication and i am planning for my final year project a research on how traffic (signaling) in a specific cell in a cellular network can be sent to another cell when there is a huge congestion like in a...

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...

Homework Statement Identical plates are placed close together on ice. A 0.742 kg rabbit that is initially sitting on the plate on the left jumps to the other plate and immediately back to the original plate. The rabbit leaves both plates with a horizontal component of velocity of magnitude...

The escape speed from a very small asteroid is only 22 m/s. If you throw a rock away from the asteroid at a speed of 30 m/s, what will be its final speed? all i know is K+U = 0 i have no clue how to do this

Homework Statement A skier leaves the ramp of a ski jump with a velocity of 10.9 m/s, 13.9° above the horizontal. The slope is inclined at 48.4°, and air resistance is negligible. Calculate the velocity components just before the landing. Enter the x-component (horizontal) first and then the...

A crate with a mass of 120 kg glides through a space station with a speed of 2.5 m/s. An astronaut speeds it up by pushing on it from behind with a force of 250 N, continually pushing with this force through a distance of 7 m. The astronaut moves around to the front of the crate and slows the...

A truck covers 80 m in 17 s while smoothly slowing down to a final speed of 5.6 m/s a ) find its original speed b) Final its acceleration I want check my answer : a ) Dx = 80 m t = 17 s v = 5.6 m/s v0= ?? by appling the rule Dx = 1/2(v+v0)t 80 = 1/2(5.6 + v0) 17 v0 =...

Homework Statement A spring with a spring-constant 2.5 N/cm is compressed 35 cm and released. The 4 kg mass skids down the frictional incline of height 37 cm and inclined at a 20◦ angle. The acceleration of gravity is 9.8 m/s2 . The path is frictionless except for a distance of 0.5 m along the...

Homework Statement A spring with a spring-constant 2.9 N/cm is compressed 34 cm and released. The 9 kg mass skids down the frictional incline of height 30 cm and inclined at a 24◦ angle. The acceleration of gravity is 9.8 m/s2 . The path is frictionless except for a distance of 0.8 m along...

Final distance between two charged, identical particles approaching each other Homework Statement Two identical particles, each with a mass of 4.5 mg and a charge of 30 nC, are moving directly toward each other with equal speeds of 4.0 m/s at an instant when the distance separating the two...

Homework Statement For a,b elements of the real numbers, define a~b if \left|a-b\right|\leq 1. Determine if we have an equivalence relation. Homework Equations The Attempt at a Solution I've already done the first two parts of determining. it's only the last part that I'm having...

1. A lab was performed where students roller an initially stationary cart down a ramp 1.84m long. It took 1.15s to roll off the end of the ramp. What is the final velocity of the cart? vi=0m/s, D=1.84m, t=1.15s vf=? 2. Vav=d/t, Vav= (vi+vf)/2 3. Vav= 1.84m/1.15s=1.6m/s...

Homework Statement An 9.30 kg body moving at 9.30 m/s begins to decelerates uniformly. After 9.30 s the body is 9.30 m from the location were it started to decelerate. What is the final speed of the body 9.30 s after it started to decelerate? Homework Equations I'm not sure what...

Homework Statement A 75Kg skier starts down a 50m high 10˚ slope. What is his speed at the bottom? Part A: Consider skis frictionless Part B: Assume that the coefficient of kinetic friction between the skis and the surface of the slope is µk=.05Homework Equations |Ff|=µk•|FN|...

hi!... friends.. am new to this phyisics forum.. can anyone assist me in doing ma final year project? please give me some basic ideas to start with... thanks in advance..

Assuming that the speed of the electrons is zero as they are emitted from the filament and that as they reach the anode it is v, find an expression relating the final speed v to the charge on an electron, the mass of an electron and deltaV, and hence calculate the speed v of the electrons after...

The drawing shows two thermally insulated tanks. drawing is located at: http://www.webassign.net/CJ/14_26.gif They are connected by a valve that is initially closed. Each tank contains neon gas at the pressure, temperature, and volume indicated in the drawing. When the valve is opened, the...

Homework Statement This problem is from the 2010 AMC 12 High school math competition: A frog makes 3 jumps, each exactly 1 meter long. The directions of the jumps are chosen independently at random. What is the probability that the frog's final position is no more than 1 meter from its...

Let's consider a second order differential equation f(x,\dot x,\ddot x,t)=0 and let's suppose that f satisfies all the conditions of the Cauchy Theorem, i.e. f is such that the equation above with the initial conditions x(t_0)=x_0\qquad\dot x(t_0)=v_0 has an unique solution in a...

Hi, I don't know if this is the right place to ask this.. As the title says, I want know the final velocities of two partcles after collision, but I want to get those from the impulse, not from the final velocities equations you see arround there... The final step would be that: Vf =...

I encountered a problem related to merchandise allocation. We are given the present available quantity of an item and its demand for every store. Quantity to be allocated is also given. The requirement is to allocate units in such a way that the "final available quantity-Demand%" is the same for...

Let me explain my situation in short terms. 1. to get a degree here(malaysia), we'll need to work on an undergraduate final year project which is sort of alike thesis? basically an undergraduate research program. 2. I like theoretical or computational physics. Well, perhaps the math, quantum...

PLEASE HELP ME TO ANSWER THIS QUESTION I AM STUCK An ice cube of 75 g is drop into a glass containing 330 g of water at a temperature of 22 ' Celsius. The ice is at 0 ' Celsius and melts so that the temperature of the water decreases. Calculate the final temperature of the water when all...

Homework Statement A rock is tossed straight up with a speed of 20 m/s. When it returns, it falls into a hole 10 m deep. What is the rock's velocity as it hits the bottom of the hole? Homework Equations V = Vo + at Y - Yo = Vot + .5at2 v2 = vo2 + 2a(Y - Yo) Y - Yo = .5(Vo + V)t...

Homework Statement A 54.0 g ice cube, initially at 0°C, is dropped into a Styrofoam cup containing 327 g of water, initially at 19.4°C. What is the final temperature of the water, if no heat is transferred to the Styrofoam or the surroundings? Homework Equations Q=mc(delta)T...

Homework Statement A rock climber stands on top of a 50-m-high cliff overhanging a pool of water. He throws two stones vertically downward 1.0 s apart and observes they cause a single splash. The initial speed of the first stone was 2.0 m/s. a) How long after the release of the first stone...

http://www.nag.co.uk/sc22wg5/ It looks like Fortran 2008 is going through its final steps of standardization. What does this mean for scientific computing? Since people still use Fortran 90 despite new revisions up to 2003, will this go under the radar, or will this be a new and useful...

Homework Statement A 5 g lead bullet moving at 343 m/s is stopped in a block of wood. All of the kinetic energy goes into heat energy added to the bullet. The initial temperature of the bullet is 24 degrees C. What is the final temperature of the bullet in degrees C? (cPb = 0.128 kJ/kg . K...

I had a question about the final value theorem: lim sF(s) S->0 = lim F(t) t->infinity I was told I can only use this if I know that a final value exists for f, or in other words that f(infinity) exists. How can I check if it exists? If I have F(s), the only way...

i'm about 1.5-2 years away from graduation and I'm thinking about what i might build for my senior project. i was thinking of a pneumatic vehicle of some sort, maybe a go cart or motorcycle, which uses modified pneumatic wrenches as motors. some of these wrenches seem to make a decent amount...

Our team are doing "Electric Powered Wheelbarrow". Can some one help me where can find the theory. This Wheelbarrow using electric engine instead of petrol or diesel engine. 1.) Where can find the dimension of the wheelbarrow? 2.) 2D or 3D Drawing? I just want the drawing that shows every...

Whatever you think of the shuttle as an effective way of getting stuff to orbit it's still a cool piece of engineering. Here is a time-lapse movie of it's last day at work. http://www.airspacemag.com/multimedia/videos/Go-For-Launch.html ps. sorry you have to watch a 20sec ad first...

Homework Statement Its the end of the year in my AP chemistry class and one section of our lab final includes finding the molar mass of an unknown gas. we are given a balloon filled with the gas and we must conduct any tests to figure the molar mass outHomework Equations pv=nrt i believe the...

Homework Statement A student pulled a box of books weighing 68kg by a rope at an angle of 58 degrees above the horizontal plane of the floor. The floor has a coefficient of kinetic friction of µk=.27. What is the acceleration of the box of books? Homework Equations ∑F = ma Force...

Hello, I am going to be taking the ACS physical chemistry exam in a few days and am trying to find out the materrial that will be on it. The ACS website leaves out a lot of stuff in there description.

I am taking an undergrad course P Chem II: Quantum Chemistry and Spectroscopy...and the final is a standardized exam from the ACS. I was just wondering if you guys had any tips or knew where to find old exams to practice with. I just was looking for any advice in general too. Thanks a bunch!

Oxygen gas having a volume of 1000 cm3 at 45.0°C and 1.01 *10^5 Pa expands until its volume is 1450 cm3 and its pressure is 1.06 * 10^5 Pa. a) Find the final temperature of the sample. t2 = (p2v1/p1v1) * t1t2 = [(1.06*10^5 * 1450 *10^-6) / (1.01*10^5 * 1000 *10^-6)] * 318.2 = 484.2I input...

Homework Statement Two balls roll towards each other. Ball A moves to the right with velocity 5 m/s and ball B moves to the left with velocity 3m/s. If both balls have the same mass, m=50kg, determine the final velocity of them if they move off together after collision. In which direction will...

Hello people, this is my first post here in PF and I have a problem with the modeling of a pulley system considering the friction between wire and pulley. I have a similar system as show in the image below and I have a friction factor of 0.25 between wire and pulley, my question is, how can I...

Homework Statement A man pushes a chair that weighs 60N with a force of 25N. The chair has a final speed of 4.0m/s. and a kinetic friction of .27. What is the acceleration? Homework Equations i have no idea where to start, i tired this formula that had me find distance but the...

Firstly, do gamma rays spread out evenly or do they spread in random directions? Secondly, how do I test the effect of gamma ray radiations intensity at different direction in a way comparable to the effect of light intensity on an LDR? thanks!

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Homework Statement A high-pressure gas cylinder contains 20 ℓ of toxic gas at a pressure of 1.8 \times 10^7 Pa and a temperature of 24 °C. Its valve cracks when the cylinder is dropped. The cylinder is cooled to dry ice temperature (–78.5 °C) to reduce the leak rate and pressure so that it...