Impulse Definition and 905 Threads

In my ODE course I learned that for a time invariant operator p(D), if p(D)x=q(t) then p(D)\dot{x}=\dot{q}(t). Then the professor "justified" that the derivative of the unit step response, v(t), is the unit impulse response, w(t), because the derivative of unit step function is the Dirac...

Homework Statement I took a test today and I am pretty sure I got everything right except for this one problem that was on there which I am unsure of. If I remember correctly, it went like this: It said there was a particle of mass 2 kg moving with a speed of 5 m/s to the right. Then there...

Thunderstorm During a violent thunderstorm, hail of diameter 2.0 cm falls directly downward at a speed of 25 m/s. There are estimated to be 120 hailstones per cubic meter of air. (a) What is the mass of each hailstone (density = 0.92 g/cm3)? (b) Assuming that the hail does not...

Been stuck on this question for days and any help would be greatly appreciated A baseball going horizontally at 32.0 m/s [E] with a mass of 0.152 kg is hit by a bat for 0.002 seconds. the velocity after the ball after contact is 52.0 m/s [W 20 N] Find the impulse experienced by the ball...

If you were in a car, and you hit a bug. Compared to the force that acts on the bug, how much force acts on the bus, is it greater lesser or equal?

Let u(t) = \begin{Bmatrix} 1, & t \geq 0 \\ 0, & t<0 \end{Bmatrix} and let's have a simple circuit. Solo capacitor, connected to a DC voltage U0, a switch S exists. For purposes of this problem, I can mark the voltage across the capacitor as Vc(t) Vc(t)=u(t)*U0 Current...

Kim holds a 2.0 kg air rifle loosely and fires a bullet of mass 1.0 g. The muzzle velocity of the bullet is 150 m/s. What is the recoil spped of the rifle? The next shot the girl holds the rifle tightly against her body. Calculate the new recoil speed assuming the girl has a mass of 48kg. I'm...

Homework Statement A fast ball is pitched at a batter who hits a pop fly vertically into the air. The ball was moving horizontally at 38.45 m/s when it was hit by the bat. As it left the bat it was moving vertically and reached a maximum height of 44.196m. The mass of a baseball is 0.1417 kg...

Homework Statement Impulse is defined as: force x time a) Find its unit expressed in term of the base units. b) What quantity has the same unit? What could it mean? (Impulse = change in momentum) Homework Equations I = F x T P = mv The Attempt at a Solution a) First, we...

Homework Statement The impulse on a human cannon ball is 2.5  103 N·s. The cannon ball has a mass of 65 kg. Homework Equations How long is the barrel of the cannon if the cannon ball leaves the cannon at 120 km/h? The Attempt at a Solution I used the formula J=ma(delta t)...

I know the fact that, if the total strength of the nerve signal exceeds the threshold at axon hillock, it triggers an action potential. But if someone asks me a question about axon being the nerve impulse generator or the structure responsible for transfer of information, then I would say that...

Homework Statement A mass 100.0 g is dropped from some height above the ground and rebounds to a point where it has 78% of its initial gravitational potential energy. As it hits the ground, it is moving at 1.2 m/s. What is the impulse imparted by the ground on the ball? Homework...

Hello! Homework Statement After the cable snaps and the safety system fails, an elevator cab free falls from a height of 36m. During the collision at the bottom of the elevator shaft, a 90 kg passenger is stopped in 0.005 s. Assume that neither the passenger nor the cab rebounds. What are...

I'm only interested in the 2d representation of this, as I will be applying whatever I learn to a physics engine Anyways, I know that a block resting on a flat surface will have a normal force acting on it equal to its weight However, I'm not interested in gravity But, say a block comes...

Homework Statement Question:A 2,800kg car is traveling at a velocity of 22m/s. The car hits the wall and comes to a complete stop. The collision took 0.3 seconds. a. What is the cars impulse? b. What force did the wall exert on the car? c. What force did the car exert on the wall? d...

1)anyone tells me what is the differences between impulse and impulsive force?? 2) impulsive force = force X time momentum = mass X change in velocity impulse force = momentum. i know why but i don't understand why impulsive force is same as momemtum, if i want to decribe something...

Homework Statement Calculate the change in momentum of a 120g pool ball hitting at 9m/s and rebounding at 6m/s. It rebounds at an equal and opposite angle of 45 degrees. Pi = 9m/s Pf = 6m/s angle = 45 degrees Homework Equations The Attempt at a Solution I have done all my...

Homework Statement A player bounces a 0.47 kg soccer ball off her head, changing the velocity of the ball from vi= (8.8 m/s)x + (-2.4 m/s)y to vf= (5.0 m/s)x + (3.0 m/s)y. If the ball is in contact with the player's head for 6.7 ms, what is the direction of the impulse delivered to...

Homework Statement A proton has mass 1.7×10−27 kg. What is the magnitude of the impulse required to increase its speed from 0.991c to 0.994c? Homework Equations Impulse = mV_f{}-mV_i{} The Attempt at a Solution Impulse = mV_f{}-mV_i{} = 1.7e-27*(.994*3e8)-(1.7e-27*(.991*3e8)) =...

Homework Statement If, when catching the ball, the child applied triple the force, then the length of time that it would have taken to slow the ball would have been: A. 9t B. 3t C. 1/3t D. 1/9t Homework Equations Impulse = Net force x Change in time The Attempt at a Solution...

Hi there, I'm aware that a hypothetical antimatter rocket could have a specific impulse of ~1,000,000 seconds. At first I thought that this would be the highest isp possible as antimatter/matter collision releases all the energy in the mass. However as wikipedia put's it "It is not...

Whats the difference between a discrete time impulse and a continuous time impulse signal ?

Hi, This is my first post. Sorry for the mistakes it certainly contains. I have two questions. First, is there a tutorial for using embedded LaTex? I found some general tutorials on LaTex, but I couldn't get some of the commands listed in that tutorial to work in the embedded LaTex code...

Hi, This is my first post. Sorry for the mistakes it certainly contains. I have two questions. First, is there a tutorial for using embedded LaTex? I found some general tutorials on LaTex, but I couldn't get some of the commands listed in that tutorial to work in the embedded LaTex code...

Homework Statement A 0.30 kg potato speed changes from 6.0 m/s to 2.0 m/s. What is the linear impulse of the potato Homework Equations The Attempt at a Solution mv(final) - mv(initial) .3 * 2-.3 * 6 = This gives me the change but after that I am lost... any help?

Homework Statement A 0.060-kg handball is thrown straight toward a wall with a speed of 11 m/s. It rebounds straight backward at a speed of 8.6 m/s. (c) The rebounding ball is caught by a player who brings it to rest. During the process, her hand moves back 0.40 m. What is the impulse...

hi, i have trouble in understanding the concepts of the impulse response first of all, let's assume that we have a signal y[n] = x[n] which is time invariant and linear, hence if I understand correctly linear means that if for input a*x1[n] we have an output a*y1[n] b*x2[n] we...

Homework Statement \int \delta(t)^{2} [SIZE="6"]dt from -infinity to +infinty Homework Equations \int^{\infty}_{-\infty}\delta(t)dt = 1 \int uv dt = u\int v dt - \int u^{'}(t)\int v dt dt \int^{b}_{a} f(x) dx = F(b) - F(a) \delta(-\infty) = \delta(\infty) = 0 The...

I am trying to teach myself DSP, owing to bad lecture notes. In particular at the moment I'm trying to calculate impulse responses for LTI systems, given the system equation. I would really appreciate it if someone could tell me if my working and assumptions below are correct for the following...

Homework Statement Hi all :biggrin: The Attempt at a Solution First of all, can someone tell me how to get the eqn in hint? :redface: And when i try solving it using the hint ... of ball (velocity of separation) = e(velocity of approach) v' = e √(2gh) = √(gh/2) let the...

Homework Statement i have this graph http://img858.imageshack.us/img858/1346/56954457.png and i need to find h-1[k] i don't understand, i know that the impulse response is the response for input -> δ[n], in this case it will be δ[n+1], but i don't understand how to calulate the response...

A tennis player is able to exert an average force of 28N when hitting a ball. Calculate the impulse if the racket is in contact with the ball for 0.1 seconds: Then I did: 28 x 0.1 and got 2.8 kg m/s. The follow up question was: A 70 g tennis ball comes toward the player at 30 m/s and it hit...

Homework Statement A 2kg object is moving to the right with a speed of 4 m/s when it experiences an impulse of 6 Ns . Homework Equations mv+mv=mv The Attempt at a Solution Since the impulse is just the change in momentum I put in 2(4)+2v=6 so wouldn't v be -1?

Find h[n], the unit impulse response of the system descrived by the following equation: y[n]+3y[n-1]+2y[n-2]=x[n]+3x[n-1]+3x[n-2] Can this be rewritten as?(n-->n+2) y[n+2]+3y[n+1]+2y[n]=x[n+2]+3x[n+1]+3x[n]

Homework Statement A horizontal force of 0.80 N is required to move a mass M2 = 5kg across the surface with a constant acceleration. With the block initially at rest, a 0.02kg bullet M1 fired horizontally into the block causes the block (with bullet inside) to slide 1.5m before coming to rest...

Homework Statement A long jump trial, the vertical ground reaction force of an athlete’s take-off leg was measured as shown below. At foot strike, the horizontal velocity of the take -off leg was 8.00 m/s and the vertical velocity of the take-off leg was -2.30 m/s. (Chart as Attachment)...

Homework Statement Find the impulse response of the following: Assume the system is initially at rest. y[n] - (1/2) y[n-1] = x[n] + 2 x[n-1] + x[n-2] The Attempt at a Solution To find the impulse response y[n]: we know that y[n] = homogenous solution + particular solution so... lamda -...

Homework Statement Two skaters stand in the center of a circular rink of frictionless ice. When the skaters push on one another, they move apart along the same straight line. If the skater of mass m1 = 50 kg reaches the edge of the rink after 12 seconds and the other skater reaches the...

Homework Statement So the problem asks to find the impulse response h(t) provided y(t) = integral from -infinity to t of e^-(t-tau)*x(tau-2)dtau Homework Equations none The Attempt at a Solution I understand that the way to begin this problem is to substitute delta(t) for x(t). Therefore the...

Imagine there are 2 space-probes in space. Both of them start their engines in the same time. The first space-probe has a very low level of thrust but a very high specific impulse. The second space probe has a very high thrust but a very low specific impulse. Both of them have an equal amount...

Homework Statement A tennis player returns a 30m/s serve back at 25 m/s after making contact with the ball for .5 seconds. If the ball has a mass of .20kg, what is the force exerted on the ball? Homework Equations I = Force\DeltaTime, or essentially the \DeltaMomentum = Impulse P=M*V...

Homework Statement This is a two part question. Kim holds a 2.0kg air rifle loosely and fires a bullet of mass 1.0g. The muzzle velocity of the bullet is 150m/s. What is the recoil speed of the rifle? ^ I got -.075m/s Part Two: If Kim in the previous questions holds the rifle tightly...

Hey guys, could anyone please explain this to me? Homework Statement Two girls with masses of 50kg and 70kg are at rest on frictionless in line skates. The larger girl pushes the smaller girl so that the latter rolls away at a speed of 10m/s. What is the effect of the action on the larger...

Homework Statement A car is brought from 100 km/h to 0 km/h in 2 seconds. A student with a mass of 73kg(not wearing a seat belt) flies through the air toward the dashboard which is 0.650m away. He smashes into the dashboard and it takes 0.25 seconds to slow him to the velocity of the car at...

Homework Statement A 261 g hockey puck is sliding on ice with a speed of 5.34 m/s hits a wall at an angle of 27.3° to the wall and bounces back at the same angle with the same speed. a) If the wall and the hockey puck are in contact for 10.9 ms, find the magnitude of the impulse on the...

Homework Statement Find the unut impulse response h[n] of this system y[n+1]+2y[n]=x[n] Homework Equations I have no clue on how to slove this problem, som pointers would be nice. Thx

i am given the Laplace transform of an impulse response function, as well as its input. i am supposed to find its output. H(s) = 1/s2 + s + 1 x(t) = sin2(t-1)U(t-1) what i have done so far is the following: i know that Y(s) = H(s)X(s) and from this i can easily find y(t) so i found X(s)...

Although I'm sure people have been looking to develop a solution like this since the beginning of time (at least, the first use of electricity), I'm trying to achieve a design that will enable perpetual electricity generation without the addition of conventional energy inputs. Essentially, I'm...

Homework Statement Two men of equal masses m stand on a platform of mass M. Both men jump with the same horizontal velocity with respect to the platform. Find the relation between velocities of the platform if they jump simultaneously and if they jump one after the other. Homework...

Hi all The impulse response h(t) of an electric circuit (maybe in some special cases) is the derivative of the step response s(t) of the same circuit. right? So does it mean they have different dimension, namely if the dimension of s(t) is X, then the dimension of h(t)=ds/dt is x over...