1d motion Definition and 25 Threads

##v=\frac12 *1*4+\frac12*1*4= 4 m/s## but the answer is wrong.

Homework Statement We have that a police car is traveling at ##26.4## m/s, and that at a time, ##t=0##, a car speeds by at ##37.5## m/s. After ##1## s, the police car accelerates constantly at ##2## m/s2. We are asked to find the time, ##t##, where the police car catches the speeder. Homework...

Homework Statement In outer space, a ball with mass 0.25kg and charge +4/K C is shot from 5m towards a +0.5C charged ball with an initial velocity of 20 m/s What main Physics principle should be used to solve this problem? What is the closest the small ball will get to the large one? What is...

Homework Statement 2 cars with velocities 10 m/s and 20 m/s are traveling in opposite directions, having uniform retardation of 2m/s^2 and 1m/s^2 respectively. Find minimum separation between them such that they don't collide. Homework Equations $$v^2=u^2 + 2as$$ $$V_{12}=v_{1}-v_{2}$$ The...

Homework Statement A particle is moving along the x axis. Its velocity as a function of time is given by v = 5+10t , where v is in m/s. The position of the particle at t = 0 sec is 20 m. Find (a) the acceleration as a function of time (b)the position as a function of time (c) the velocity of...

Homework Statement [/B] A baseball of mass m is thrown straight up with an initial velocity v0. Assuming that the air drag on the ball varies quadratically with speed (f = cv^2), show that the speed varies with height according to the equations. Where x_{0} is the highest point and k = c/m...

Homework Statement At the instant the traffic light turns green, Stan Speedy starts from rest and accelerates at "as". At the same instant Kathy Kool passes Stan with constant velocity "vk". Given: [as, vk] How far beyond the starting point do they meet again? Homework Equations...

i have L of particle m in 1D motion, but how i can find the coordinate of particle x at time t?

Suppose a particle is moving along the $x$ axis with velocity $v$. It starts at the point $-5$ and has constant negative acceleration $a$. You need to find what time the particle reaches the origin. My teacher solved this question, and used the kinematics equation Δx = v_0t+1/2 at^2...

Homework Statement basket ball player throws a ball up in the air and the ball travels 3.2meters before stopping. if the basketball player jumps .5 seconds after throwing the ball. what velocity does he need to reach the ball. Homework Equations vf^2=v1^2+2as sf=si+vot+1/2at^2 vf=vi+aot...

Homework Statement a rock is thrown nearly vertical upward from the edge of a tall building of height H. it just misses the edge of the building on the way down and strikes the ground T seconds after being thrown. given H, T determine the initial velocity of the rock the max height it reaches...

Homework Statement at the instant the traffic light turns green, s starts from rest and accels at a_s. at the same time k passes s with constant velocity v_k. given a_s, v_k, find distance before the cross again time it takes to do so velocity of s at this point plot the position as...

Homework Statement Give example of a motion where x>0, v<0, a>0 at a particular instant. x-->Position v-->Velocity a-->Acceleration Homework Equations I thought I had to give an example such as a car, ball etc. But the answer says: x(t) ie; position for time t; given by...

All, I am reviewing for a comprehensive exam and am extremely weak on 1D Motion. Can you please help me out? A lab cart travels along the x-axis and its position as a function of time is given by the following expression: x(t)= 6m - (8 m/s)t + (1 m/s2)t2 1. Displacement of cart during time...

Homework Statement A car making a 94-km journey travels 39 km/h for the first 47 km. How fast must it go during the second 47 km to average 51 km/h? Homework Equations The Attempt at a Solution

All are true false but need help on all of them thanks in advance 1)Knowing the position and velocity of a particle allows its future position to be predicted even if its acceleration is unknown. 2)Instaneous velocity is the derivative of the displacement time function. 3)If the...

1. The problem statement I am studying for an upcoming test and I am having a lot of trouble relating velocity, acceleration, and displacement vs time. Given a position vs time function: x(t) = 6m - (8m/s)t + (1m/s^2)t^2 I cannot for the life of me understand how to find any instantaneous...

Problem 1 A commuter train travels between two downtown stations. Because the stations are only 1.00 km apart, the train never reaches its maximum possible cruising speed. During rush hour the engineer minimizes the travel interval Δt between the two stations by accelerating for a time interval...

[SOLVED] Very beginner physics 1D motion question! Homework Statement Two cars move in opposite directions toward each other on a level, straight, one-lane road. When both drivers begin to brake, their front bumpers are 275 meters apart. The smaller car is initially moving at 25.0 m/s and the...

Homework Statement A police car leaves in pursuit of a holdup car 0.50 h after the latter has left the scene of the crime at 120 km/h. How fast must the police car go if it is to catch up with the holdup car in 1.00h? Homework EquationsI'm thinking Vf=Vo+at? i must be wrong, I can't seem to...

FUN 1d motion prob--help Homework Statement The figure (http://img471.imageshack.us/my.php?image=picprobfd5.png) shows a general situation where a stream of people attempt to escape through a door that is closed. The people move toward the door at a speed of v = 3.50 m/s, are each d = .25 m...

INTRODUCTION: This is a problem from my Introduction to Physical Science class using "Conceptual Physics" 10th Ed.by Paul G. Hewitt EXACT PROBLEM: "The coefficient of kinetic friction between a rubber tire and a wet concrete road is 0.5." PROBLEMS FACED: a) Find the minimum time in...

Consider the one dimensional motion of a particle in the potential V(x)=D(e^{-2ax}-2e^{-ax}). I'm supposed to obtain the expressions for x as a function of time separately for the cases that the total energy E is positive, zero or negative. I have used \frac{1}{2}m\dot{x}^2 + V(x) -...

47. A rock is dropped from a sea cliff and the sound of it striking the ocean is heard 3.4s later. If the speed of sound is 340 m/s, how high is the cliff? Could somebody map this one out for me, it isn't making any sense.

The question goes as follows: A truck covers 40.0 m in 8.50 s while smoothly slowing down to final speed +2.40 m/s. Find the original speed Find the acceleration Now, I tried a couple things for the speed, I tried 40/8.50, and I tried (4.71/2.40) and both turned out to be wrong. Not...