Initial Definition and 1000 Threads

hi there! i can't quite recall the formula for vertical velocity and who to easily factor the polynomials. Help anyone? here's my example problem: A cricket jumps off the ground with an initial vertical velocity of 4 ft per second. A. write an equation that gives the height (in feet) of the...

I was reading Stephen Hawking offers new resolution of black hole paradox. Most is over my head but when he mentions particles falling in through the EH, it raises a question. When a BH is created in a collapsing star, does the EH first appear at zero radius and grow outward, or does the EH...

Homework Statement Homework Equations I know that this could be solved through kinematics. The Attempt at a Solution I thought that I could use the range equation to solve for Vo, but since there is an initial height, I don't think that could work. I thought that maybe I could use the...

Homework Statement :[/B] I would like to know if the definition of the ZSR response means that the initial condition at any t0 needs to be 0.Homework Equations :[/B] let's say : we're trying to calculate the ZSR response from a first order equation of the voltage of a capacitor and the initial...

Hello guys, I'd just like to ask how can I formulate transfer function of second order differential system when I don't have zero initial conditions? the equation is = y''(t) + B/m*y'(t) + k/m*y(t) = g y(0)= -L don't care what parameters mean .. it's supposed to be solved in general Thank...

Homework Statement A 20.0-kg block is connected to a 30.0-kg block by a string that passes over a light frictionless pulley. The 30.0-kg block is connected to a spring that has negligible mass and a force constant of 250 N/m. The spring is unstretched when the system is as shown in the figure...

The ODE is $y'' + 4y' - 12y = 0$, I get $y = C_1e^{-6x} + C_2e^{2} $ The initial conditions are y(0) = 1, y(1)=2 - which gives me $C_1 = 1-C_2$ and $C_2 = \frac{2e^{6}-1}{e^{8}-1} $ This just looks more messy than book exercises normally are, and when I laboriously substitute back into the...

Homework Statement A referee throws a ball in a basketball game. When the ball was in his hand the heigh was 1,6 meters above the ground. The ball is caught 0.8 seconds later by a jumping player. The ball is 2.7 meters above the ground and on the way down. what was the initial velocity when the...

Dear all, I am trying to understand the physics behind the "number density" formula given by Weinberg. Is there anyone who can explain these parameters to me: 1- "Initial fluctuation strength": \begin{equation} \rho_1= \lim_{t \to 0}\frac{\Delta \rho_M^3}{\bar{\rho}^2_M}\end{equation} However...

Homework Statement We need to fin the initial velocity of a water fountain. The data I have collected is: Height (bottom to apex)= 0.042 m Distance (from spout to end on the stream)= 0.112 m Time (it takes to travel)= .25 seconds Angle the water shoots from= 50 degrees Here is more if it...

Homework Statement Solve \begin{equation*} 36x^2y''+(5-9x^2)y=0 \end{equation*} using the Frobenius method Homework Equations Assume a solution of the form \begin{equation*} y=\sum_{n=0}^{\infty}{a_nx^{n+s}} \end{equation*} then \begin{equation*}...

what are ramifications of exclusions on SUSY gluino mass 1.8 TEV to MSSM and other SUSY-SM and higgs hirearchy?

Homework Statement Frog jumps in air to 1m height. Neglecting air resistance find initial speed the instant it leaves the ground. a= -9.8m/s^2 d= 1m vi=? Homework Equations d=1/2(vf+vi)t d=1/2at^2 + vi(t) + di The Attempt at a Solution I figured that since acceleration is 9.8m/s, I could just...

Homework Statement This is a solution to a problem that was on a quiz, and I am confused about how to do it. Especially lines two (<0,1,1>=v(0)=<C1, 1+C2, C3> --> C1=0, C2=0, C3=1 and five (<1,0,0>=r(0)=<1+ K1, K2, K3> -->K1=0, K2=0, K3=0 How do you do these steps...

Firstly, my main question boils down to speaking about the initial conditions and boundary conditions. I was given: $$ u(0,y,t) = u(\pi,y,t) = u(x,0,t) = u(x,\pi,t) = 0 $$ but then the initial condition was: $$ u(x,y,0) = 1 $$ Aren't the initial and boundary conditions inconsistent in such...

Homework Statement Two independent sources are given. They are active at different times. Find the conditions at t = 0- DCSS (aka t < 0 DCSS) and t = ∞ DCSS for IL and Vc Homework Equations At DCSS, replace inductor with short circuit At DCSS, replace capacitor with open circuit The...

Homework Statement A hole is punched in a full milk carton, 10cm below the top. What's the initial velocity of outflow? Homework Equations P2 = P1 + ρgh Conservation of energy of fluids: P2 + 1/2ρv22 + ρgy2 = P1 + 1/2ρv12 + ρgy1 The Attempt at a Solution Set the top of the carton as P1, and...

I know the method and can solve other initial value problems. This is the question given: dy/dx + y(-2) Sin(3x) = 0 for t > 0, with y(0) = 2. I've brought the dy/dx and let it equal to the rest of the expression so it is now: dy/dx = -y-2 Sin(3x) , with y(0) = 2 (i.e. when x = 0, y = 2 ) The...

Homework Statement Complete a free body diagram for the truss structure with a weight attached to node 2 (this is known as 151N) Homework EquationsThe Attempt at a Solution I have attached my Free Body Diagram The diagram is to display what is know at the start of the problem before working...

Homework Statement A system consists of a bicycle and a cyclist traveling at a constant velocity along a horizontal road. The total resistive force acting on the system in 4.0N and its speed is 8.0 m/s. Calculate the useful power output of the cyclist. The cyclist stops pedalling and the...

Homework Statement A 1.15-kg grinding wheel 22.0 cm in diameter is spinning counterclockwise at a rate of 20.0 revolutions per second. When the power to the grinder is turned off, the grinding wheel slows with constant angular acceleration and takes 80.0 s to come to a rest. (a) What was the...

Homework Statement In an oscillating series RLC circuit, with resistance R and inductance L, find the time required for the maximum energy in the capacitor during an oscillation to fall to 1/5 its initial value. Assume q = Q at t = 0 Homework Equations ## U(t) =...

Homework Statement So there are two planets A and B whose centres are 6r apart. A and B has the same mass M and radius R. What is the minimum velocity(from the surface of B) of the rocket required to launch it from B so that it reaches A ? Homework Equations F=GmM/R^2 The Attempt at a...

Homework Statement A 1500-kg sedan goes through a wide intersection traveling from north to south when it is hit by a 2200-kg SUV traveling from east to west. The two cars become embellished due to the impact and slide as one thereafter. On-the-scene measurements show that the coefficient of...

Homework Statement To work out the intial acceleration, do we just use the equation: So at t = 0 We eliminate the wt inside the bracket, and are left with Aω^(2)sin(Φ + π) Homework EquationsThe Attempt at a Solution The part which I'm not so sure on, is if i have values for Φ, do i...

Homework Statement Three identical charged balls of mass m and charge q bound in a triangle thread length l. One of the strands break. Calculate the acceleration of the middle ball at the initial moment. 2. Relevant equation a. Newton's laws ##m\vec a_1 = \vec F_{12} +\vec F_{13} + \vec...

Hello, I'm struggling with a simple problem here. It asks me to solve the following initial value problem: So far I've calculated the integration factor μ(x) = ex-x2 and I multiplied both sides of the equation by it and got this...

Hi! I just started studying physics in German, and I am stuck about basic formulas partially because of the language. 1. Homework Statement A ball is launched from the ground at a speed |vb0| = 90m/s with an angle of β = 50° to the horizontal axis x. At a distance of d = 60m is placed a...

Homework Statement 1 mm3 of gas at normal pressure and temperature contains about 1015 particles. Considering the particles as point-like and classical, provide a rough, conservative estimate for how many hard drives would be necessary to store the initial conditions of all gas particles. (As...

Homework Statement Use laplace transforms to find following initial value problem -- there is no credit for partial fractions. (i assume my teach is against using it..) y'' - 4y' + 3y = 0 ; y(0)=2 y'(0) = 8 Homework Equations Lf'' = ((s^2)*F) - s*f(0) - f'(0) Lf' = sF -...

Please help me solve this differential equation for the initial condition (0,-1): dx/dy = ((1+x^2)^(1/2))/(xy^3) I think I'm doing something wrong because I end up with ((x^2)(y^3))/2 = ((x^2)+y)^(1/2) + c, but when plugging in the initial condition it ends up being the square root of...

I've put the problem statement below and worked it out. I typically don't post questions like this as they're a lot to go through, but I am wondering if I have worked the problem correctly as my book does not have the solution and I feel like I am not understand the material correctly. 1...

Homework Statement Two cannons(A at inital height h; B at initial heigt h/2) fire(horizontally), B firing with higher velocity than A. Homework Equations 1) If they fire at the same time, is it possible that the projectiles collide? 2) Is it possible for B to delay his shot so that his...

Homework Statement Solve the initial value problem and determine at least approximately where the solution is valid (2x-y) + (2y-x)y' = 0 y(1) = 3 Homework EquationsThe Attempt at a Solution I know how to solve it, and I got the correct answer, which was: 7 = x^2 - yx + y^2 and then applying...

Homework Statement I need to find two ways to calculate initial velocities (2 versions) of an object just clearing over a 9.99 m wall. Homework Equations kinematics equations The Attempt at a Solution Way 1 I was trying is to say dx = 40m , dy = 10m, ay= -9.81m/s^2. The thing is, I can't...

Homework Statement : [/B] Find two elevation angles that will enable a shell, fired from ground level with a muzzle speed of 800 ft/s, to hit a groundlevel target 10,000 ft away. Homework Equations Look at attached picture The Attempt at a Solution Look at attached picture ***I get to...

Hello, I have a question regarding the solution to a second order 'mass-spring-damper' system. Over the years, I have gotten familiar with the idea of system damping in the sense of under damped, over damped, and critically damped systems. However, I've began looking closer at the solution to...

Hi, We normally use a simple symmetry argument to show that the probability of each outcome of a throw of a fair, cube-shaped die is 1/6. However, is it possible to actually model the physics of the throw and show that the probabilities are 1/6? Since this is classical physics, the outcome can...

Homework Statement What is the initial velocity of the ball just as it enters the screen? The Job Using your understanding of projectile motion along with some background research on video analysis, devise a way to find the initial velocity of the tennis ball in the video just as it enters...

Homework Statement I am attempting to understand this example shown below: Homework Equations During stead state DC, the capacitor is an open circuit and the inductor is short circuited. The Attempt at a Solution [/B] The questions I have are really related to the concepts as I don't...

So if you have an object in a hot air balloon that it traveling upwards at constant velocity, and this object falls out of the hot air balloon, is its initial velocity 0 or is it the same as that of the balloon? Thanks in advance!

Let's consider a hadronically decaying tau at ATLAS. Is it possible for the product jet's ##p_T## to be larger than the tau's one?

I have put together an equation whose purpose is: With a desired 'magnitude of static friction' ( μ_s ), 'fundamental frequency' ( f ), and 'tension' ( T ), initial conditions such as 'string breakover angle' ( Θ_0 ), 'nut-tuner distance' ( L_{h,0} ), and 'string diameter' ( d ), and...

I've been trying to come up with the answer but it hasn't gotten me anywhere. I know that I need to find the angle to get the velocity. Q: A rock is projected from the edge of a 30.48 m tall building at some unknown angle above the horizontal. 5 seconds after, the rock strikes the ground at a...

Assume the population of bacteria in a culture increases at a rate proportional to the current population. The population increased by 2455 from t = 2 to t = 3 and by 4314 from t = 4 to t =5. Find the initial population and how many times does the population increase each unit of time? I don't...

1. The prIoblem statement, all variables and given/known data You are the chief of the Angry Birds (Google it, if you don’t know the reference...it’s not important). You can shoot red birds from a catapult, and they will fly as projectiles under the effect of gravity. Gravity points downwards...

Homework Statement Homework EquationsThe Attempt at a Solution The question says block B has negligible mass ,which means particle will be effectively in free fall i.e acceleration would be 'g' . But then it is given a horizontal velocity i.e it has centripetal acceleration ac about the...

Homework Statement Sam heaves a shot with weight 16-lb straight upward, giving it a constant upward acceleration from rest of 45.4 m/s^2 for a height 65.0 cm . He releases it at height 2.16 m above the ground. You may ignore air resistance. Q-What is the speed of the shot when he releases it...

Homework Statement A flat roof has a height of 65m above the ground. A tennis ball rolls off the edge of the roof and hits the ground at a point 418m horizontally from the edge of the roof. A.) How much time is the ball in the air? B.) What is the magnitude of the initial velocity?[/B]2. The...

Homework Statement At which minimum velocity should you throw the ball horizontally if you are standing on a hemispherical rock of radius R so that it at no point touches the rock and lands at the minimum distance from the rock horizontally. Find the expression that solves for initial velocity...