Constant velocity Definition and 199 Threads

Homework Statement A 10 N force is horizontally applied to a cart from the left. The cart moves to the right with a constant velocity. What is the magnitude and direction of the frictional force? (In terms of mass) Homework Equations Fnet=ma fk=ukN The Attempt at a Solution I know Newton's...

Homework Statement The Position Function of a spaceship is r(t) = (5t+9)i+(2t2-1)j+t2k and the coordinates of a space station are P(54,89,45). The captain wants the spaceship to reach the space station in constant velocity. When should the engines be turned off? Homework Equations r'(t)...

As I understand it, friction is the force that accelerates cars on a road. Assuming that the car moves at a constant velocity, there is no net force on the car. But in this case, if friction acts to accelerate the car, what force acts to retard the car's motion? Surely it can't be purely the...

Homework Statement A 25.6-kg boy pulls a 4.81-kg toboggan up a hill inclined at 25.7º to the horizontal. The vertical height of the hill is 27.3 m and the coefficient of friction of the hill surface is 0.4 a) Determine how much work the boy must apply on the toboggan to pull it at a constant...

the questions I have are general questions regarding power and velocity here are some relevant equations: P=Fv a) if the force required to keep an object in motion with a constant velocity does not depend on the speed of the object, does the power required to keep the object moving in at a...

When a potential difference is applied across a conductor. then a electric field[/color] is formed across it. There are free electrons in conductor which should accelerate because of there is electric field. Since all we know that Force =charge*Electric_field. But it is not so. Inside a...

A 20 kg mass is sitting on the horizontal surface of a table top. Calculate the following Neglecting friction, calculate the force required to give the mass a velocity of 2ms. So far all I can think of is... F=ma m=20kg a=? a= Vf-Vi / t ... I am stuck ... all I can think of is F =...

Homework Statement As a participant in a robotic competition, you must launch a potato from a moving cart and strike a target. The potato must reach the apex of flight just as it travels over a screen, then it must pass through the center of an opening in a wall. The cart moves at a steady...

Homework Statement A bead, under the influence of gravity, slides along a frictionless wire whose height is given by the function y(x). Assume that at position (x,y) = (0,0), the wire is horizontal and the bead passes this point with a given speed v0 to the right. What should the shape of the...

Homework Statement The given data is a graph depicting the distance (km) that a bus travels over 3.5 hours. The trip is broken up into three linear segments. I am supposed to find the average acceleration over the entire trip in km/hr^2. I am told that the answer will be negative. Edit...

Say you're pushing a heavy desk (225kg) across a carpeted floor. You either push it at 3m/s (say you applied a 675N force for 1sec, so you apply the force for 1.5m), or at 6 m/s (you applied 1350N force for 1sec, so the force is applied over 3m). After that one second impulse, however, you...

(a) Suppose that a NASCAR race car is moving to the right with a constant velocity of +81 m/s. What is the average acceleration of the car? (b) Twelve seconds later, the car is halfway around the track and traveling in the opposite direction with the same speed. What is the average acceleration...

Homework Statement "Jim leaves at noon and drives east on I-10 at 60mph, Jenny leaves from the same location at 1:30PM, but travels at 70mph. When and where will Jenny catch up to Jim?" Homework Equations None. The Attempt at a Solution When doing a similar problem in class, we...

Can anyone show me how to calculate the magnetic field of a single charge moving at a constant velocity - including both the current and displacement current terms? Also, what is the significance if any of this result to Galilean vs Lorentz transformations? It seems like a problem that...

(not a homework question, just something I thought about) http://img23.imageshack.us/img23/1130/hellhell.jpg So, if I'm told that the helicopter here let's go of an object and he wants the object to hit the truck. (all objects are "point mass"). Can I say right from the get go that, as...

This is in a question of finding retarded potential where the point charge is moving at constant velocity. The book let the charge pass through the origin at t=0 so \vec w(t) = \vec v(t) which I don't understand. This might be a stupid question. velocity is a vector with amplitude and...

I want to know the comparison between a body in motion with constant velocity and accelerated motion? Like a body when it is motion with constant velocity its velocity is constant(v =constant) and acceleration (a=0)...? and when a body is in accelerated motion its velocity will be constant(v...

Homework Statement Stuntman's Freefall, a ride at Six Flags Great Adventure in NewJersey, stands 39.6 meters high. Ignoring the force of friction, what is the minimum power rating of the motor that raises the 1.20×105kg ride from the ground to the top in 10.0 seconds at a constant velocity...

Homework Statement Would constant velocity down a slope be achieved by a cart, by having the frictional force equal to that of Wsinθ (Where W is the weight force and θ is the angle between the slope and the horizontal). Homework Equations/The Attempt at a Solution For example if θ...

Homework Statement a car with a constant velocity of 1m/s, accidentally hits a huge block with a mass of 300kg. Instead of stopping the driver constantly maintain the speed, pushing the block along the way until the car runs out of fuel. Find the force applied in the block if the coefficient...

Homework Statement Hi. My task is to find the Force F, so that velocity is constant. I know that the velocity is constant, therefore the sum of all forces must be zero! On the image I have used vector decomposition (the black lines). The orange ones are the vectors. I know that the...

Hi Folks, What I have here is a multiple choice question from a practice test. I believe there to be two right answers but the answer key says there's only 1. I'm not looking for anyone to do my homework for me, I just think there is a mistake. Here we go: The hands of a clock _______...

Homework Statement A particle with mass 5kg travels with a constant velocity of 5 m xˆ − 2 m zˆ while ss subject to a force of 1Nxˆ − 5Nyˆ + 6Nzˆ . At what rate is this force doing work on the particle? Homework Equations w = fd The Attempt at a Solution I changed it into vector...

Homework Statement A farm tractor tows a 3900kg trailer up a 16degree incline with a steady speed of 3.0 m/s. What force does the tractor exert on the trailer? (Ignore friction) Homework Equations F=ma W=mg The Attempt at a Solution I haven't the slightest clue on where to start

Homework Statement Two students are traveling along a straight line path. One at .9m/s, the other at 1.9 m/s. How far does the faster student travel in order to arrive at the destination in 5.5 min. Homework Equations I was using x=Vx X t for each students path and subtracting the...

Homework Statement Please help! This is my question! It is common to see birds of prey rising upward on thermals. The paths they take may be spiral-like. You can model the spiral motion as uniform circular motion combined with a constant upward velocity. Assume a bird completes a circle of...

Homework Statement Two dogs stand facing each other 85 meters apart. They begin to run towards each other. Dog A runs at a constant velocity of 3.5 m/s; Dog B is going the opposite direction at a constant -2.8 m/s. How long before the dogs collide? Homework Equations Xfinal-Xinitial =...

Homework Statement A train pulls away from a station with a constant acceleration of 0.41 m/s2. A passenger arrives at a point next to the track 6.4 s after the end of the train has passed the very same point. What is the slowest constant speed at which she can run and still catch the train...

Homework Statement A red car and a green car, identical except for the color, move toward each other in adjacent lanes and parallel to an x axis. At time t = 0, the red car is at xr = 0 and the green car is at xg = 220 m. If the red car has a constant velocity of +20 km/h, the cars pass each...

How to find the degree of inclination if there is only coefficient of kinetic of friction is given & a constant velocity? the coefficient of kinetic friction between a wooden box and an inclined plane is 0.30. At what angle will the box slide with a constant velocity once set in motion?

Hi, everyone We were told in class that the Coriolis Effect is due to the change in the radius in circular motion. But an objtct moving with constant velocity on the edje of the circular system, like on the equator still experiencing Coriolis force, because the cross product 2wXv is not...

Since heat is a form of electromagnetic radiation, does it travel at the constant velocity of light?

I was recently asked this question: If there is no net force on a system which is moving at a constant velocity, which of the following is also constant? a) Acceleration b) Momentum c) Impulse d) All of the above My solution: a) Acceleration must be constant via Newton's Second law. Since...

Homework Statement "The 100- dash can be run by the best sprinters in 10.0 . A 64- sprinter accelerates uniformly for the first 41 to reach top speed, which he maintains for the remaining 59 ." What is the average horizontal component of force exerted on his feet by the ground during...

According to Sir Newton, F = ma i.e if a body needs to be accelerated it requires some force basically. or in reverse can we say that if a body needs to exert some force, it must have some acceleration.?? then does it means a body moving with constant vel can't exert force on other body.?

It seems to me that it is highly likely that everything in the universe is acted upon by gravity, unremittingly. Since gravity causes objects having mass to accelerate it would appear that a constant velocity for these type of objects is not possible. Can anyone explain my conundrum ?

Homework Statement You drag a suitcase of mass 17 kg with a force of F at an angle 40.6◦ with respect to the horizontal along a surface with kinetic coefficient of friction 0.59. The acceleration of gravity is 9.8 m/s2 . If the suitcase is moving with constant ve- locity 2.68 m/s, what...

Homework Statement "You push a 325-N trunk up a 20.0 degree inclined plane at a constant velocity by exerting a 211-N force parallel to the plane's surface." What force must be exerted on said trunk so that it would slide down the plane with a constant velocity? In which direction should the...

One of the scenarios that I've come across while reading about special relativity is the scenario of a person riding on a train undergoing constant velocity motion, such that the person in a train car with all windows drawn is unaware that their train car is moving at all. The car is not...

Homework Statement Ok so the problem is this: A car of a mass 960kg is free-wheeling down an incline (15 degrees to the horizontal) at a constant speed of 9.0 m s^-1 - Deduce that the average resistive force acting on the car is 2.4*10^3N Homework Equations F=ma I suppose, but it hasn't...

Homework Statement There is one particle traveling at a constant velocity. Its velocity vector and initial position are known. A second particle needs to collide with the first particle. We know the initial position of this particle, and the speed (magnitude of velocity). Find the direction...

Homework Statement Prove that 2 motorized toy cars have a constant velocity. A car was set up at a marked spot, then turned on and left to go for 3m. This was done three separate times and was timed using 2 timers (2 people). how can i prove a constant velocity? I have the averages for both...

Homework Statement A horizontal force of 20 N is required to move an object with a mass of 8 kg along a horizontal floor with constant velocity. Find the coefficient of kinetic friction. Homework Equations f = uN u = f/N The Attempt at a Solution u = 20 N/(8 kg X 9.8 m/s2) u = 20 N/78.4 N...

This is probably very simple, but it's causing me problems. I keep coming up with VERY unrealistic times. Any help would be greatly appreciated! One simple model for a person running the 100 m dash is to assume the sprinter runs with constant acceleration until reaching top speed, then...

Homework Statement A cyclist is traveling along a straight horizontal road. as she passes a bus stop she sees a red traffic light ahead of her. She continues to travel with a constand speed of 3 ms^-1 for 20 seconds and then decelerates at a constant rate of 0.2ns^-2 until coming to rest at...

Homework Statement A physics student playing with an air hockey table (a frictionless surface) finds that if she gives the puck a velocity of 3.79 m/s along the length ( 1.84 m) of the table at one end, by the time it has reached the other end the puck has drifted a distance 2.47 cm to the...

how would we calculate the force if something was moving at a constant velocity and hit a wall or the ground , i know that if the velocity was constant there is no force but if it hit a wall or something , would this just be a change in momentum p=mv

Would a signal sent from a transmitter, traveling at constant velocity toward an observer, arrive at the same time if it were accelerating toward that observer? The signals are sent at the same relative distance from the observer. Would the result be the same if the transmitters were receding...

Hello, i have an idea but i ran into a bit of a problem. I need two unidirectional output shafts rotating at unpredictable varying velocities (but predictable within a range) to be able to combine at one output shaft. I have come up with some ideas but they tend to be quite complicated... any...

if, a particular body rotates ,with a certain velocity then every particle of that moves with the same velocity as that of body.if the Earth is moving at a velocity,we also move with same velocity daily . for eg:the speed of light was discovered to be 3x10^8m/s wrt to earth,but is it the...