Kinematics Definition and 1000 Threads

Homework Statement Hi everyone, I am doing a lab currently (and it looks like a few other people on here have had similar questions...) and I'm having trouble with one of the concepts. I had to drop a ball from a height and measure the movement with a motion sensor, which was graphed with the...

Homework Statement A circular space hotel in orbit around the Earth has a radius of 220m. in order to produce "fake gravity" along the outer rim, it is desired to rotate at a speed that will produce a centripetal acceleration of 9.81 m/s^2. A) find the tangential speed of appoint on the rim...

In cases like projectile motion, although the acceleration vector is constant (ignoring air resistance), a single coordinate axis fails to describe the motion of the particle, since it occurs in a plane; therefore we need a minimum of two coordinate axes to fully describe the trajectory of that...

1. A cat walks in a straight line, which we shall call the x-axis with the positive direction to the right. As an observant physicist, you make measurements of this cat's motion and construct a graph of the feline's velocity as a function of time the figure...

Homework Statement You place a m=2kg block at the bottom of a playground slide and give it a quick kick, giving it an initial speed of vi=12m/s. The slide is inclined at an angle of 35 degrees and the coefficient of kinetic friction between the block and the slide is mu_k=0.2. Use g=9.8m/s/s...

Homework Statement Justin is racing Mark. Justin accelerates from rest at the starting point at 1.2 m/s^2 [E]. Mark is still adjusting his equipment and 2.0 s later begins to accelerate at 1.5 m/s^2 [E]. Where and when does Mark catch up to Justin? Homework EquationsThe Attempt at a Solution I...

Homework Statement Two masses are placed on top of a building. The mass of one is twice the mass of the other. Both are dropped at the same time. Neglecting air resistance, which statements are true? 1. Both objects have the same potential energy at the top 2. Both objects fall with the same...

Homework Statement A ball launched from ground level lands 2.85s later on a level field 48 m away from the launch point. Find the magnitude of the initial velocity vector and the angle it is above the horizontal. (Ignore any effects due to air resistance.) Homework Equations...

Homework Statement A soccer ball is kicked from the ground at an angle of 30◦ with speed 30m/s. Determine the duration of the flight, range and maximal height of the trajectory. Homework EquationsThe Attempt at a Solution 1. Break down the velocity vector into x and y components: 30cos(30) =...

Homework Statement A robotic bug is moving along the x-axis. Its equation of motion is x(t) = 10*t^2- 4*t - 6 I have a problem with only one question: What is the distance covered by the bug between t = 0.1 s and t = 0.4 s? Homework EquationsThe Attempt at a Solution [/B] The first...

A truck and a car both start from rest at the same time on a straight track. The car is 25.0 m behind the truck at the start. The truck accelerates at 3.70 m/s^2 and the car accelerates at 4.40 m/s^2. How long does it take for the car to catch up to the truck? Hey all, first post, didn't think...

Homework Statement So I am stuck on this homework problem. I understand the general direction I have to take, but my algebra and physics aren't good. Here's the problem: A simple Atwood's machine uses two masses, m1 and m2. Starting from rest, the speed of the two masses is 10.0 m/s at the end...

Homework Statement Block B has acceleration of 4 m/s2... Relative acceleration of block A w/ respect to B is 4 m/s2. Find magnitude & direction of accel for A? Homework Equations a_A = a_B + a_A/B x_A = x_B + x_A/B y_A = y_B + y_A/B The Attempt at a Solution x & y components: -4cos(20) =...

Homework Statement : Block B has acceleration of 4 m/s2... Relative acceleration of block A w/ respect to B is 4 m/s2. Find magnitude & direction of accel for A?[/B] Homework Equations a_A = a_B + a_A/B[/B]The Attempt at a Solution a_A = 4 +4 = 8 m/s2 <-- 8*cos(20) = 7.52 (x-component)...

Homework Statement A ship is traveling across the sea when its engines are cut. The ship slows down by a = -kV2. The ship gradually slows down from 5 knots/h to 12 knots/h over 20min. Determine the distance traveled in nautical miles. One knot is 1 nautical mile per hour.Homework Equations...

Homework Statement In which case car engine must do more work: To start driving from 0 kmph until car reaches 27 kmph or to reach 54 kmph from 27 kmph? Force of resistance in both cases are equal. I need to base answer of this problem on formulas. I apologize for any grammar mistakes (i'm not...

Homework Statement A lift ascends from rest with uniform acceleration of 4m/s², then it moves with uniform velocity and finally comes to rest with uniform retardation of 4m/s². If the total distance covered during ascending by the lift is 28m and the total time for ascending 8s respectively...

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?

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 >[/color] 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...

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...