Initial velocity Definition and 451 Threads

Homework Statement A man jumps from a building into a safety net located at 11m below, that acts like a rigid body when the man hits it. Find the speed. The safety net moving 1.5m meters down stops the man completely. Find the deceleration, assumed as constant.Homework Equations Vf2= Vi2+ 2ad...

Homework Statement (this is translated from Italian so it might have some technical mistakes :) ) A target with negligible dimensions is placed at H = 5m from the ground; a vehicle on the ground is moving at a velocity V = 2m/s (the module) and is getting closer to the target. Consider O the...

Homework Statement A car traveling at 88ft/s skids 176ft after its brakes are applied. The deceleration provided by the braking system is constant. What is its value? The Attempt at a Solution $$ v_0=88 \\ v_f=0 \\ d_0=0 \\ d_f=176 $$ $$ d(t)=\int88\,dt \\ d(t)=88t+c...

Homework Statement (b) A particle is projected from a point O at time t = 0 and it performs simple harmonic motion with O as a centre of oscillation. The motion is of amplitude 20cm and time period 4 seconds. Find: (i) the speed of projection; (ii) the speed of particle when t = 1:5...

Homework Statement distance = 0.8meters angle = 55° gravity = 9.81m/s^2 \V_0 = ?, assuming that it leaves and falls back on the same horizontal plane. The attempt at a solution So we know for a fact that the initial velocity is supposed to be 2 m/s, according to the book at least. I tried...

A circus clown in a cannon is shot vertically upward with an initial speed of 18.0 m/s. after ascending 4.5 m ,she collides with and grabs a performer sitting still on a trapeze. They acend together and then fall. what is their speed when they reached the original launch height. The clown and...

I read in a article that Earth revolves around the sun at speed of 30km/s but from where did it get its velocity at the beginning..?

x(t)=Acos(ωt+ϕ)\\ v(t)=-Aωsin(ωt+ϕ)\\ \\ Let\quad n=integer,\quad A=0.5,\quad ω=2.\\ \\ Given\quad initial\quad position\quad (0,\quad 0.25)\quad and\quad initial\quad velocity\quad (0,\quad 1),\quad find\quad ϕ.\\ \\ x(t)=0.5cos(2t+ϕ)\\ 0.25=0.5cos(ϕ)\\ ϕ=±1.0471975512+2πn\\ \\...

Homework Statement A ballistic pendulum is used to measure the speed of a bullet fired from a gun. The pendulum consists of a 20.0g block hanging from a string. A bullet, with mass 0.50gg, imbeds itself in the block causing the block to swing up to a height of 5.00cm. Find the speed of the...

In the figure, a frictionless roller coaster car of mass m = 800 kg tops the first hill with speed v0 = 18 m/s at height h = 44 m. What is the speed of the car at point B? (point B is one half the height of the top of the first hill) (1/2)mv2 Wg=mgd (1/2)(800)(182)=129600...

Homework Statement "An athlete executing a long jump leaves the ground at a 30.0° angle and travels a horizontal distance 8.00m. What was the take-off speed?" Let ##x=## horizontal distance ##v=## velocity ##a=## acceleration Known: ##x=8 m## ##x_0=0 m## ##a_y=-9.8 m/s^2##...

Homework Statement http://postimage.org/image/466vu4yvp/ http://postimage.org/image/opdrmlv5n/ There can be more than one right answer Homework Equations α=Δv/ΔX v = v0 + αt The Attempt at a Solution Im having difficulty understanding the upward acceleration vector. Because I set the +y...

On a spacecraft two engines fire for a time of 572 s. One gives the craft an acceleration in the x direction of ax = 5.15 m/s2, while the other produces an acceleration in the y direction of ay = 7.41 m/s2. At the end of the firing period, the craft has velocity components of vx = 3782 m/s and...

Hi, I don't know what I'm doing wrong but these significant figures seem to be screwing me up. Problem: A bike rider accelerates constantly to a velocity of 7.5 m/s during 4.5 s. The bike's displacement is +19 m. What was the initial velocity of the bike? The textbook says the answer is 0.94...

Homework Statement See: http://www.aapt.org/physicsteam/2010/upload/2010_FmaSolutions.pdf #15, 16 Homework Equations U_o + K_o = U + K v_CoM = vM1 + vM2 / (M1 + M2) The Attempt at a Solution I thought that for 15 it was simply: 1/2mv^2 = mgh h = v^2/2g But this is wrong, so...

Homework Statement A bullet of mass 12.0 grams is traveling with a speed V0 and strikes a block of mass M = 1.00 kg that rests on a horizontal surface (mu = 0.40). After the bullet imbeds in the block, it slides 2.60 meters before coming to rest. The initial velocity of the bullet must have...

Homework Statement A child on a 4m long swing is pulled back 1m from the vertical and released with a push imparting a speed of 2m/s. Find an expression for the angle θ, as a function of time, identifying the frequency ω, amplitude θi, and phase constant δ. Homework Equations θ =...

Homework Statement A bean bag launcher is used to shoot a bean bag at a corn hole board. The bag is released at a height of .61m above the ground. The front of the board is 5.18m from the location where the launcher releases the bean bag. The back of the board stands .31 m off the ground; the...

Homework Statement An object that is thrown covers a distance of 8.59 m. If the angle at which it is thrown is 23 degrees, what is its initial velocity? Homework Equations 5 kinematic equations: a = (v2-v1)/t d=0.5(v1+v2)t d=v1t+0.5at^2 d=v2t-0.5at^2 v2^2=v1^2+2ad Equation for...

Homework Statement A grasshopper jumps 1.00 meters from rest, with an initial velocity at a 45.0° angle with respect to the horizontal. Find (a) the initial speed of the grasshopper and (b) the maximum height reached.Homework Equations vx = v0xt = v0cos θ0 vy = v0 sin θ0 - gtThe Attempt at a...

Hi there, This is a problem concerning hyperbolic type partial differential equations. Currently I am studying the book of S. J. Farlow "Partial differential equations for scientists and engineers". The attached pages show my problems. Fig. 18.4 from case two (which starts in the lower part...

Homework Statement Consider an electron that has its position measured to within a nuclear radius in a laboratory. What is the uncertainty in its position uncertainty one day later? Homework Equations The Attempt at a Solution What equation should I use to determine the...

Homework Statement This is a homework that has me completely stumped. If anyone help me out here, I would greatly appreicate it. A billard ball is east at 2.0 m/s. A second, idential ball is shot west at 1.0 m/s. The balls have a glancing collision (not head-on), deflecting the second ball...

Homework Statement I need help finding the x and y components of initial velocity being given the angle the trajectory was fired at and the distance the projectile traveled. For this example I'm using an angle of 15° and the projectile travels 0.534m. I'm not sure if I'm going in the right...

I am doing a projectile motion problem with my own results, and the unknown's of initial velocity and time. It is at 0 degrees, which I thought would mean I could find the vertical down of the projectile (where at an angle you find the vertical up and down because it goes up first). I have tried...

Homework Statement A cannon ball weighing 128 pounds is fired from a cannon at 45 degrees above the horizontal. The cannon ball lands in a pool that has a radius of 14 feet and located 7.5 feet above the ground. The closest edge of the net is 98 feet from the cannon. It takes 4 seconds for the...

1. Homework Statement A basketball player is standing 9.5 m from the basket, which is at a height of 3.1m. she throws the ball from a initial height of 2m at an angle of 35 degrees above the horizontal. The ball goes through the basket. Determine intial velocity. 2. Homework...

Homework Statement A basketball player is standing 9.5 m from the basket, which is at a height of 3.1m. she throws the ball from a initial height of 2m at an angle of 35 degrees above the horizontal. The ball goes through the basket. Determine intial velocity. PS Assume the max height of the...

Homework Statement In the figure below, what is the minimum initial speed of the dart if it is to hit the monkey before the monkey hits the ground, which is 12.2 m below the initial position of the monkey, if x is 48 m and h = 11 m? (Ignore any effects due to air resistance.) Use this figure...

Homework Statement Assume there is a wall located 100m downrange (x=100) from the projectile launching position (x=0) that is 55m (y=55) high. What is the minimum initial velocity of the projectile launched at what angle necessary to clear the wall? Homework Equations h=(v^2sin^2α)/2g...

Homework Statement A basketball player throws a ball at an angle of 30º above the horizontal. If the ball in has an initial velocity of 29.4 m/s, how far does it travel? Homework Equations Vyf^2 = Vyi^2 + 2(Ay)(Dy) solve for Dy and get [Vyf^2 - (Vyi^2)] / (2(Ay)) = Dy The Attempt at a...

Homework Statement A projectile was fired across level ground at an initial angle of 43.00 degrees above the horizontal. During its flight, it reached a maximum height of 2974 metres. What was the initial speed of this projectile? Homework Equations I assume that the correct equation...

Hello everyone, I was doing some experiment using a spring compressed gun, that shoots up ball beraings. I made it using a desoldering pump and a PVC pipe,its quite small. ok, so I set it in 45° angles for maximum range. A desoldering pump has a spring inside, when you push down on top the...

Homework Statement A football player punts the football so that it will have a time of flight = 4.5s and land 45.7m away. The ball leaves the player's foot 1.52 m above ground. What is initial velocity? (Magnitude and direction) Homework Equations x-x_0 = v_0 * cosθ * t y-y_0 =...

1. My problem is I know displacement is 20m, acceleration is -5.4m/s, final velocity is 0m/s, coefficient of friction=0.55, the object slowing down weighs 1000kg, can I find initial velocity and the time it took to slow down and if so how? I have no idea how to go about this problem 2. Equations...

Hi everyone, I am having trouble finding the answer to a homework problem. I don't seem to understand what the question is exactly asking for. The problem is: find the path of a particle with an initial position 10er + 1.0eϴ and an initial velocity 0.1er + 0.8eϴ

Homework Statement I need to calculate the initial velocity required to launch a projectile at a given angle from point A to point B. The only force acting on the projectile after launch will be gravity – zero air resistance. The projectile is launched within a simulated, virtual environment...

how to get to Vo = the square root of ((xa)/(sin2theta)) from the kinematic equations or form SinTheta =Voy/Vo CosTheta =Vox/Vo just really confused. I am writing a formal lab for my final and what I am asking is find the initial velocity it would take for the object to hit the target as a...

Homework Statement A train which weighs 1.4406E4N hit a car with a mass of1470kg. The cars skids 15m at angle of 68° to the crossing and the coefficient of friction between the tyres and the road is 0.25. Find the initial velocity of the car entering the crossing. Homework Equations...

Homework Statement An object takes 12.3 meters to stop because of friction. Assume no skidding. If the coefficient of static friction is 0.86, what is the initial velocity of the object? Homework Equations initial velocity= mu*m*t The Attempt at a Solution

Homework Statement A golfer hits a ball, giving it a maximum height of 20 m. If the ball lands 130 m away at the level from which he hit it, what was its initial velocity? (Neglect air resistance) Homework Equations The Attempt at a Solution I found the angle to be 31.6, so I...

1. Homework Statement A soccer ball is kicked at 38.0° with respect to the horizontal and travels 64.0m before striking the ground. a) what is its initial velocity? b) how long was it in the air? 2. Homework Equations dv=1/2*at2 dh=Vh*Δt Kinetic equation d=Vi*t+ 1/2*at2...

Homework Statement A soccer ball is kicked at 38.0° with respect to the horizontal and travels 64.0m before striking the ground. a) what is its initial velocity? b) how long was it in the air? Homework Equations dv=1/2*at2 dh=Vh*Δt Kinetic equation d=Vi*t+ 1/2*at2 dh=-V2*sin2θ /g...

For a harmonic oscillator with mass M, spring of stiffness k and displacement the force equation is: -kx = Md2x/dt2 How do you handle the situation and work out a solution for x(t) when the mass has an initial velocity. E.g. a mass dropped onto the spring?

Homework Statement A cannon ball is fired horizontally off the top of a cliff that is 400 m high above the ocean. The ball hits the water 600 m away. With what speed does the cannon ball enter the water? Homework Equations I've tried using d_{x} = u_{x}*t d_{y} = u_{y}*t +...

Homework Statement A 1.428 kg textbook is kicked 183 centimeters, what is the initial velocity right as it left the foot? Homework Equations fk-ma/W Vf^2=Vo^2*2aΔx The Attempt at a Solution We were given no time, no acceleration, and no force. I'm completely at a loss! this is what I have...

Homework Statement a golf ball is shot from a height of 6.5 ft above the ground at an angle of 45° above the horizontal. The ball lands 39 ft and 3 inches downfield. Assuming ideal projectile motion find: a. Initial velocity b. flight time c. maximum height Homework Equations r =...

I can do with just an equation, but if anyone is willing to help: Target is 25.6 m away from canon Initial Velocity = 16 m/s Time = 2.6 s Range = 26.7m No air resistance

I can do with just an equation, but if anyone is willing to help: Target is 25.6 m away from canon Initial Velocity = 16 m/s Time = 2.6 s Range = 26.7m No air resistance

I'm trying to understand a problem someone gave me recently. there is a frictionless track that initially starts flat then there is an incline of 20 degrees then it levels out again at the bottom of the incline. you have two masses, 1 is .4 kg and is located at the top of the hill and has an...