Kinematic Definition and 406 Threads

Homework Statement A skater jumps off a quarterpipe ramp and reaches 5m over the ramp. We can assume that he jumps in a vertical line. Find the speed the skater had before jumping off the ramp. Homework Equations https://www.physicsforums.com/threads/introductory-physics-formulary.110015/ All...

Mod note: Moved from technical section, so no template Question: The ace Edward bow can shoot 182.8 meters at a 45 degree angle, it can shoot 12 arrow per minute. What is the performance of the Bow? Attempt: Basically considering the Dx=182.8 meters I assume the Dy is the same considering its...

Homework Statement Problem states : A student walks off the top of the CN Tower in Toronto, which has height h and falls freely. His initial velocity is zero. The Rocketeer arrives at the scene a time of t later and dives off the top of the tower to save the student. The Rocketeer leaves the...

Hello Forum, I have a couple of kinematics questions. The position of a point object is given by the position vector x(t). Speed is v(t)=dx(t)/dt and the acceleration a(t)= dv(t)/dt. What if we wanted to know the velocity and/or the acceleration as a function of position, i.e v(x) or a(x)...

As I know, when a link in a kinematic chain is fixed, the kinematic chain will become a mechanism. And, I only know the definition of the DOF of a mechanism. Is there the definition of the DOF of a kinematic chain ?

Homework Statement Marie is running to catch a bus. The bus has stopped at a bus stop. The bus has the acceleration 0.75m/s^2. Marie has the speed 8m/s. Before the bus starts driving, the space between Marie and the bus is 17.5m. A How long will it take for Marie to catch up to the bus? B What...

1. A rock is dropped into a well of an unknown depth. 20 seconds after the rock is dropped the splash is heard at the top of the well. What is the depth of the well? What is the velocity of the rock when it reached the bottom?2. X= Xo + Vo(t) + 0.5(a)(t^2) V= Vo + a(t) (V^2)= (Vo^2) + 2a(X-Xo)...

Homework Statement Picture yourself in the castle of Helm's Deep from the Lord of the Rings. You are on top of the castle wall and are dropping rocks on assorted monsters that are 19.10 m below you. Just when you release a rock, an archer located exactly below you shoots an arrow straight up...

Homework Statement [/B] A boy drops a 0.10 kg stone down a 150 m well and listens for the echo. If the speed of sound is 343 degrees Celsius, the how long after the stone is dropped will the boy hear the echo? Homework Equations v = d/t v2 = v2 + 2ax The Attempt at a Solution [/B] What I...

Homework Statement A cops and robbers chase is set up as follows 1. Both the police car and the robber's can start from rest 2. The robbers have 1 km head start 3. The robber's van accelerate at 0.50 m/s 4. The police car accelerate at 0.60 m/s Use famous 5 equations to answer the...

ice skater with mass = 80 kg moment of inertia (about her central axis) 3 kg m2. Catch baseball with outstretched arm 1m from her central axis. Ball has mass 0.3 kg and v0 = 20 m/s before the catch. V system ( skater + ball ) after catch = 0.0747 m/s Question : b. Angular speed of the...

Hi! I'm working on a problem for class and am having trouble figuring out how to calculate the initial velocity, which I need in order to calculate acceleration and from there the value of an unknown force. I thought I was on the right track, but my professor reminded me that I need to use the...

Homework Statement A girl shoves a book at rest on a table and it moves with an acceleration of 1.3 m/s . After 5 s, the book falls at the edge of the table. If the table height is 1.2 m, find the horizontal distance that it hit the floor. (ans: 3.22 m) ... How the answer would be 3.22...

At time t=0 s a 0.362-kg air track glider is moving rightward at 5.1 m/s. At t=2.5 s, it's going leftward at 5.4 m/s. Determine the magnitude and direction of the constant force that acted on the glider during this interval. Give your answer in Newtons. If the force is going rightward, your...

Homework Statement A 124-kg balloon carrying a 22-kg basket is descending with a constant downward velocity of 23.5m/s A 1.0-kg stone is thrown from the basket with an initial velocity of 14.8m/s perpendicular to the path of the descending balloon, as measured relative to a person at rest in...

A fast food restaurant uses a conveyor belt to send the burgers through a grilling machine. If the grilling machine is 1.1 m long and the burgers require 2.5 min to cook, how fast must the conveyor travel? If the burgers are spaced 15 cm apart, what is the rate of of burger production (in...

Homework Statement I figured out this homework problem, after many tries, but I'm confused about the correct final answer. Here's the question: The rebounding ball, mass of 0.06 kg, traveling horizontally at 7.6 m/s, is caught by a player who brings it to rest. During the process, her hand...

Homework Statement a vehicle is traveling at 25m/s. its breaks provide an acceleration of -3.75m/s^2. What is the drivers maximum reaction time is she is to avoid hitting an obstacle 95.0m away? Homework Equations D=vi(t) +1/2a(t)^2 3. The Attempt at a Solution D=95m vi=25 m/s a=-3.75m/s ^2...

Homework Statement I'm taking my first basic physics course and I came across this simple question (which I got the wrong answer apparently). The question was this: what is the velocity and acceleration of an object which has reached it's maximum height after being thrown directly upwards...

Homework Statement A simple pendulum of length ##b## and bob with mass ##m## is attached to a massless support moving vertically upward with constant acceleration ##a##. Determine (a) the equations of motion and (b) the period for small oscillations. 2. Formulas ##U = mgh## ##T = (1/2)mv^2...

The problem goes by this: A sphere of radius ##\rho## is constrained to roll without slipping on the lower half of the inner surface of a hollow cylinder of inside radius R. Determine the Lagrangian function, the equation of constraint, and Lagrange's equations of motion. Find the frequency of...

Weird question, but does anyone have any feelings on whether parity can be classified as a kinematic property? It doesn't scale with energy and so in that sense doesn't seem to be classifiable as a dynamic property, nor do objects interact through it; but parity is of course violated by the...

Homework Statement Practice problem for midterm. Homework Equations [/B] T_1+U_1=T_2+U_2 U_spring=1/2kx^2The Attempt at a Solution [/B] Set X-axis along the 30 degree line and the Y-axis perpendicular. I'm not sure how to consider the friction constant into the formula. Any help is very...

Homework Statement A biker and his motorcycle have a weight of 2350 N [down]. Calculate the force of kinetic friction for the rubber tires and dry concrete if the motorcycle skids. (Coefficient of friction is 0.7) Homework EquationsThe Attempt at a Solution my answer i got was 1645 but the...

Homework Statement MJ falls from rest from a tall building. 1.5 seconds later SP throws himself downward with an initial velocity of -45 meters per second. Find the distance where they meet. variables: α1= -9.81 α2=-9.81 Δγ1 = ? Δγ2=? Δ†1=? Δ†2=? + 1.5 ∨i1=0...

Homework Statement A truck covers 40.0m in 7.15 s while uniformly slowing down to a final velocity of 3.50 m/s. a.) Find the truck's original speed b.) Find it's acceleration Homework Equations Δx = Vav(Δt) = (V+Vo/2)Δt a=(V-Vo)/(Δt) The Attempt at a Solution Part A.)...

Homework Statement A basketball leaves a player's hands at a height of 2.20m above the floor. The basket is 3.05m above the floor. The player likes to shoot the ball at a 35.0∘ angle.If the shot is made from a horizontal distance of 5.90m and must be accurate to ±0.22m (horizontally), what...

Homework Statement A large very powerful gun shoots a bullet that easily goes through a block. In the process the block is knocked off the post and falls to the ground. Which hits the ground first, the bullet or the block. Why? Homework Equations The Attempt at a Solution I am...

A car is traveling at 25 m/s when it runs off the road and hits a utility pole. The car stops instantly, but the driver continues to move forward at 25 m/s. The airbag starts from rest with a constant acceleration from a distance of 50 cm away from the driver and makes contact with him in 9...

Hey guys, I'm confused on this problem: It is a typical sunny day. Assume your reaction time is 0.50 s and the acceleration of your car is –8.2 m/s2. What is the no-skid stopping distance when the car’s speed is initially 26.9 m/s? Homework Statement a=-8.2 m/s^2 v0=26.9 m/s v=0...

Homework Statement Object from state of inaction starts to move with equal acceleration. If objec in 5th and 6th sec passes 20, what's acceleration. Homework Equations s=v0*t+a*t*t/2 v0=0 The Attempt at a Solution s=a*t*t/2 a=s/2 a=10

HElp With Problem 1 see image Ahora In THIS problem Part 1 without wind I understand it perfectly But where are the 10 km and 20 km come from? y b) Why do arcsin ( 40/220)?

Black hole A moves at slow velocity, and there's an Einstein light clock hovering near the event horizon. Black hole B moves at high velocity, and there's an Einstein light clock hovering near the event horizon. The black holes are identical. And the light clocks are at the same...

Hello there, I have a problem that I've been trying to solve for some time now and I find myself struggling. I am trying to develop a method of calculating the position of a particle using kinematic motion in a 2D Cartesian coordinates system given a set of starting values based on how much...

Homework Statement A stone is dropped of a cliff. A second stone is thrown down the cliff at 10 m/s at 0.5s after the first stone. When do the stones cross paths? Homework Equations Yf = vt + at^2/2 The Attempt at a Solution My logic is the set the final position Yf equal for both stones...

I understand that defining the path of a joint in a mechanism comes under the category of 'kinematic analysis'. I do not understand why engineers do this,when all they need to know is the path of the piston,piston velocity and piston acceleration(kinematic analysis). Take for example this 90...

I was trying to study vectorial kinematics in all its fullness, without decorating formulas, only deducting all vectorially through mathematical definitions. I felt much difficulty, because it's a puzzle of many pieces and I not found a embracing explanation in any book. Someone could explain to...

Homework Statement How long will an arrow be in flight if it is shot at an angle of 25 degrees above the horizontal and hits a target 50.0m away at the same elevation? Known: displacement in x-axis: 50.0m acceleration in x-axis: 0m/s2 displacement in y-axis: 0m acceleration in y-axis...

skiing both ways...conservation of energy/1D kinematic Homework Statement A skier starts from rest at the top of a 45.0-m-high hill, skis down a 30° incline into a valley, and continues up a 40.0-m-high hill. The heights of both hills are measured from the valley floor. Assume that friction...

I'm confuse by what the question is asking as far as the conversion (km/hr/s). Can any please help me? Homework Statement A jumbo jet must reach a speed of 240 km/hr on the runway for takeoff. What is the minimum constant acceleration (in km/hr/s) needed for takeoff from a 1.34 km runway...

Hey guys how's it going. My physics teacher gave us a challenge problem for extra credit, me needed the extra credit i decided to come here for help. Homework Statement here is the link to the problem itself. http://www.modelingphysics.org/consta/challenge.pdf I have actually done number...

I know that there's 5 key equations for motion which is: d = (vf+vi/2)t vf = vi + at d = vit + 1/2at^2 vf^2 = vi^2 + 2ad d = vft - 1/2at^2 Correct? But my teacher was confusing me today and he taught us these two other equations: d = 1/2(vi+vf)t d = 1/2at^2 What are...

Good evening. I'd like to first start by saying I am new to this forum, and I am a physics noob. I know that very fact will help people shy away from trying to help me answer this question. This problem (which an image is posted) is 1 of 5 questions on a take home kinematic quiz. I've managed to...

In the kinematic equation x = x0 + v0 * t + .5 * a * t^2, can someone give me an example in which x0 has a value that is not zero?

in the picture below http://tinypic.com/view.php?pic=9riq9l&s=6 if we know the angular velocity of the gear on the left, as well as their current distance from contact point, what can we say about the velocity of the right rod at the contact point at anytime t? we know it is not...

Homework Statement You are driving your car and you heavily apply the brakes for a period of 2.1 seconds. The car keeps moving for a distance of 14.6m before it completely stops. What is the acceleration (in m/s2) experienced by the car? Is it truly "acceleration"?Homework Equations 5...

So I'm given... In the y-direction vo = 0 m/s vf = 7.5 m/s (is the speed of the ball thrown straight up) g = -9.81 m/s2 (when it falls back down) yo = 0 m yf = 1.5 m (at this height above the ground, the bat connects with the ball) t = ? I tried doing this... yf = yo + vyot +...

I am testing a cylindrical piece of steel dropping down steel pipe in a vacuum system, and came across a problem comparing the kinematic equation and a standard change in velocity over change in time to determine an acceleration. My derivation shows that the kinematic equation is exactly 2...

Homework Statement See attachment, it is the question sheet. Homework Equations vf^2=vi^2+2ad d=vit+1/2at^2 vf=vi+at d=vit-1/2at^2 d=vavt The Attempt at a Solution 1. An object such as a ball let go by a person's hand falling vertically downward toward Earth has a velocity and...

Ok, so I'm using an arduino with an led matrix and a homemade pressure sensor to figure out the height of a vertical jump and then display the info back. First I get the amount of time between when the person left the board and when they land back on it. I then divide the time in half and use...