Kinematics Definition and 1000 Threads

Hello, this is my first post on PhysicsForums. I'm a first year student at the University of Kansas pursuing a Bachelor of Science in Physics and Astronomy (double majoring). The wording on my homework (for Honors General Physics 1) is a little bit strange to me so maybe some of you guys and...

Homework Statement John is thrown into the outer part of a circular den of radius a. At the centre of the den is a Lion. John decides his best tactic is to run round the perimeter of the den with his maximum speed u. The Lion responds by running towards John with its maximum speed U. (i)...

Homework Statement As a helicopter carrying a crate takes off, its vertical position (as well as the crate's) is given as: y(t)= At^3, where A is a constant and t is time with t=0 corresponding to when it leaves the ground. When the helicopter reaches a height of h = 15.0m the crate is released...

Homework Statement A freight train is moving at a constant speed of 10 m/s. A man standing on a flatcar throws a ball into the air and catches it as it falls. Relative to the flatcar, the initial vellocity of the ball is 15 m/s straight up. a. What are the magnitude and direction of the...

Homework Statement Tom throws a football to Wes, who is a distance l away. Tom can control the time of flight t of the ball by choosing any speed up to vmax and any launch angle between 0◦ and 90◦ . Ignore air resistance and assume Tom and Wes are at the same height. Which of the following...

Homework Statement Consider a cannonball being fired with a velocity of 30m/s from a cliff of height 45m. http://imgur.com/OCMNEPv (a) Calculate the time taken for the ball to reach the ground. (b) Calculate the range of the motion. (c) Calculate the horizontal velocity, vertical velocity...

Homework Statement A tree is being transported on a flatbed trailer by a landscaper. If the base of the tree slides on the trailer, the tree will fall over and be damaged. If the coefficient of static friction between the trailer and the tree is 0.5, what is the minimum stopping distance of the...

I am doing a physics project whose purpose involves describing the physics behind a toy. The toy I have selected is a "decision maker" which is composed of a pendulum which has a magnetically charged ball on it that swings side to side, while having a force exerted on it by magnets which change...

A boy jumps from rest, straight down from the top of a cliff. He falls halfway down to the water below in 0.998 s. How much time passes during his entire trip from the top down to the water? Ignore air resistance. Attempt: t = 0.998 approx 1 sec vo = 0 m/s (v initial) g = -9.8 m/s^2 I solved...

So, assume a system of two solid, spherical masses in a vacuum. Sphere A has a mass of 10 kg, and Sphere B has negligible mass in comparison. The centers of the two spheres are 10 meters apart. For the sake of simplicity, let's say that in this universe, the gravity constant, G, is 1 N*m2/kg2...

Homework Statement Golfer hits a golf ball so that it goes with initial velocity of 40 m/s at angle of 45 degrees. 100 m away is a lake that is 50 m wide. The ball will not bounce or roll when it lands. Where does the ball land? Before, in, or after the lake.Homework Equations Vertical: a =...

Okay so I have tried for hours to figure this out and can't. Please show me how to get the answers; what do I already have, what do I need, and what kinematics formula(s) do I use? Thanky ou so much! Problem: A jogger accelerates constantly to a velocity of +2.3m/s in 6.5s. After jogging 11m...

Homework Statement Given v0=0 m/s, x0=0 m, and t=10 s, use all three kinematic equations together to find xf. Homework Equations vf=v0+at xf=x0+v0t+1/2at2 vf2=v02+2a(xf-x0) The Attempt at a Solution The more I look at this, the less sense it makes. First off, I tried to plug the values into the...

So, I'm working on my semester finals for my high school physics class, and I've run across a problem that has me stumped. I've included the pertinent material below. Homework Statement A rocket with a mass of 2kg and traveling at 14,008.34 meters/second loses 10% of its velocity as finishes...

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 http://puu.sh/dzuq5/629a29dd48.png Homework Equations x = vo t + ½ a t2 2 a x= v2 - vo2[/B]The Attempt at a Solution 1/4 d = vo t + ½ a t2[/B] multiply equation by 4, d=4 ut+ 2a t2 so I am thinking answer is 4u, but it is 2u.

Hey, I'm an adult who finally realized that physics is great and tries to recall (or rather learn for the first time) what he learned at the school. I've been reading some basic things around. It's not really a homework question, I'm just trying to understand the laws here. 1. I know that if a...

Homework Statement An object starts from rest at the origin and moves in the positive x direction. The velocity is proportional to the displacment. I am trying to find the equation linking velocity to displacement. Homework Equations Since the object starts at rest and then moves in the...

Homework Statement A "rocket car" is launched along a long straight track att = 0 s. It moves with constant acceleration a1 = 2.9m/s2 .At t = 2.8s , a second car is launched with constant acceleration a2 = 7.0m/s2 . At what time does the second car catch up with the first one? How far down the...

Homework Statement A car drives off a cliff that is 100m high. It has to land in water and the water starts 30m away from the cliff. Its goal is to land 90m into the water. How fast must the car be going to land at that point in the water. Air resistance is negligible. v=0 v0=? a= -9.91m/s2...

Homework Statement I seem to have a fundamental misunderstanding of the kinematic principles in this question. A constant force of 8.0N is exerted for 4.0s on a 16-kg object initially at rest. What will the change in speed of this object be? Homework Equations F = ma Δx = v0t + 1/2 at2 Δv =...

Homework Statement A bicycle wheel is mounted as in the lab and as shown to the right. This wheel has a mass of 6.55 kg, a radius of R = 38.0 cm and is in the shape of a ring. A mass M = 1.85 kg is attached to the end of a string which is wrapped around an inner hub which has a radius r = 5.40...

Hi, I was trying to solve the following problem which was assigned to me in my Kinematics course. I found this solution for it. I understand the concept of relative velocity of the boat to the flowing river but what I really cannot understand is the trig part, of Vb/r : Vb/r = 5cos(theta)i -...

Homework Statement The ##B^+## meson decays through the weak interaction. One of its decay channels is . If a ##B^+## is traveling with a total energy of 9.90 GeV, calculate the range of possible energies the produced may have. (i.e. determine the minimum and maximum values of its energy.)...

Homework Statement Homework Equations Va = Vb + Va/b Va = Vb + (wab x ra/b) The Attempt at a Solution OK so here is part of my solution: My velocity for B is correct according to the book. But I'm confused about D. The only problem here is that the velocity of D only has an i...

In this problem why it is not considered that the bar is in translation (angular velocity = 0) if at the time when the angle is 0 °, the velocities at each point of the rod are parallel??

if any object touches the ground i.e standing on the ground,will there be acceleration due to gravity?if yes,then how much more can object go downward due to this acceleration as it is already on the floor or ground?

Disregarding air resistance, how could you find an accurate number for the initial velocity of a toy gun?

I have built a Forward kinematic block with s-function on simulink. This FK is for a pantograph. Input is two angles of the motors and output is the position and 4 angles, which are the inputed motor angles along with angles of two elbows. Now, I need a motion level FK which will output the...

1. A 1 kg wedge is pulled across a rough floor (uk=0.20) via contact with a 2 kg block as shown below. The shape of the wedge is that of an isosceles right triangle. a rope passes from the 2 kg block and over a mass-less and friction-less pulley and is attached to a hanging mass. Find the...

Homework Statement You are passing a construction site on the way to physics class, and stop to watch for a while. The construction workers appear to be going on a coffee break, and have left a large concrete block resting at the top of a wooden ramp connecting one of the building's upper...

< Moderator Note -- thread moved from General Physics to Homework Help forum > If a ball is projected vertically upwards say with a velocity V. Case 1: Without air drag Case 2: With air drag What will be the difference in v-t graphs and the motion of the ball Air drag D=bv (b is a constant,v...

Homework Statement A missle is fired vertically up from a ground with an initial velocity of 20m/s. The acceleration at any time is given by dv/dt = -10 + t/2 m/s^2. Find the height of the missile after two seconds Find the height after four seconds the direction the missile is traveling when t...

Homework Statement Crash Test Craig drives his 800kg car up a 100m ramp that is at an angle of 35 degrees above the horizontal. The car exerts a forward force of 12000N and the force of friction between the ramp and the car is 20N. He is trying to jump over a series of spinning helicopter...

Greetings all, I have been pondering this for a few days and cannot come to a conclusion. Suppose you have Frame-F with basis vectors I, J, & K. Also suppose you have Frame-B (basis vectors i, j, and k) which is rotating w.r.t. Frame-F. In such a case: i = (cos Θ)I + (sin Θ)J j = -(sin Θ)I...

Alright, the problem at a glance is rather simple: find the mechanical advantage at two given values of θ2. Given: rO2A = r2 r02C = rin rAB = r3 rO4B = r4 rO4D = rout rO2O4 = r1 θ1 = 135° Find: Mechanical advantage when θ2 is equal to 104°, and when θ2 is equal to 91°. Equations to use: Mech...

I need to obtain the forward and inverse kinematics of a pantograph device. It is easy when only the one side of the pantograph is considered; So, it becomes a 2DOF planar elbow mechanism, which is easy to solve. However, there is symmetry on pantograph, so I kinda need to combine two planar...

Homework Statement Use your calculated muzzle velocity (v_0) to determine the angle at which you would need to aim your launcher, fired from floor level, in order for your marble to land on a platform 10 cm above the floor, a horizontal distance of 50 cm from the launcher. Homework Equations...

1. A spring of spring constant k is attached to a support at the bottom of a ramp that makes an angle θ with the horizontal. A block of inertia m is pressed against the free end of the spring until the spring is compressed a distance d from its relaxed length. Call this position A. The block is...

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 Homework Equations 1/2mv^2, mgh, and basic kinematics equations The Attempt at a Solution I set the height = 0 at moment before the launch. To get the velocity, I used: energy before the ball starts accelerating (PE) = energy right before the ball leaves the ark (KE)...

Homework Statement Hi guys, I am attempting to experimentally measure torque from two rods connected to a servo. Let's say rod A stays fixed, and the servo, mounted at the end of rod A (at joint J) moves rod B to a certain angle θ with a velocity v. In addition to velocity and angle, I also...

Homework Statement A .5 kg steel block rotates on a steel table, attached to a 1.20m-long hollow tube. Air is fed through the tube and is ejected from the block, giving it a thrust force of 5.21N perpendicular to the tube. Max tension the tube can withstand without breaking is 50N. Assume...

Homework Statement A stone is thrown at an angle of 36.9 above the horizontal at 24.0 m/s from a building 56m high. What is the maximum height (with respect to the ground) that the stone reaches? Homework Equations - The Attempt at a Solution No clue. Have a picture drawn and all my knowns...

Are the vectors resolved correctly? I get a different answer to this question(well my diagram itself is different). How can ##\beta## be greater than ##\alpha##? Isn't it that here ##\alpha## should be in place of ##\beta## and ##\beta## in place of ##\alpha## and both ##V(rain,woman)## and...

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 stone is thrown straight up from the roof of a building with initial speed v0. At the same instant, a second stone is thrown from the roof upward at an angle of 60o with the horizontal and with the same initial speed v0. Which is correct? both stones hit the ground at the...

Hello everybody. Although this is just a kinematics problem, I am having a hard time figuring out what to do. The question is: An archer on the planet zorg spots an octomorph that is resting in a tree above water. The octomorph's position in the tree is 100m away horizontally and 100m...

Homework Statement Find Particle A's speed with respect to Particle B. I am given: Particle A: (15i - 10j) or 18.03 m/s angle A: -33.69 degrees Particle B: (5i + 15j) or 15.81 m/s angle B: 71.57 degrees (Both angles with respect to x axis) Homework Equations Had there not been any angles, I...

Very simple question but I am confused... I am asked to find Particle A's speed with respect to Particle B. What does this mean? I am given: Particle A: (15i - 10j) or 18.03 m/s Particle B: (5i + 15j) or 15.81 m/s I just don't understand what I'm being asked to find and how to go about solving...