# Tagged Questions

The description of the movement of bodies by their position, velocity, acceleration (and possibly higher time derivatives, such as, jerk) without concern for the underlying dynamics/forces/causes.

55 views

### Given a current velocity and a fixed input energy, how much faster will a relativistic particle be?

The relativistic kinetic energy of a particle with mass $m$ and velocity $v_0$ is $$m c^2 (\gamma_0 - 1) \textrm{ where } \gamma_0 = \frac{1}{\sqrt{1 - \frac{v_0^2}{c^2}}}$$ I would like to know how ...
43 views

### Needed acceleration input to reach a target point

I have a point mass traveling on a 2D plane with some initial velocity v and initial position r. The point mass is able to ...
69 views

### Two trains collision problem [closed]

Consider two trains $A$ and $B$ travelling on a line one towards the other at speed $v_A=v_B=90km/h=25m/s$. When they are $511m$ apart the driver $A$ start braking with deceleration ...
37 views

### Tunnel through center of the earth, how to find period using $adx=vdv$?

Suppose the boulder enters a tunnel dug through the center of the Earth along a diameter starting at rest. How would one calculate the time it takes for the boulder to reach the other end of the ...
36 views

### Methods to use in problems with equations of motion, where is required to determine a particular acceleration

I've a doubt on problems with manipulation of equations of motion. I'll make an example of a situation I'm confused about. Let $A$ and $B$ be two points that move on a line with constant speed, ...
118 views

### Position from velocity time graph [closed]

I have taken Calculus before but unfortunately no equation is given so I have to do it the old way. An object is at x = 0 at t = 0 and moves along the x axis according to the velocity-time graph ...
110 views

### How Do Low Kinetic Energy and High Kinetic Energy Atoms Attraction differ?

Will atoms of 2 difrent energy levels electron and/or Kinetic attract more than 2 Atoms at he same energy level? Do 2 high energy level atoms attract more than 2 low energy atoms?
92 views

### Equation of motion of a free particle

We know that the equation of motion of particle can be derived from the respective action. But in the book I am reading, the author is saying: ... timelike worldline of a massive particle is ...
33 views

### overtaking acceleration [closed]

A driver travelling at 50km/hr,trying to overtake another car by pressing an accelerater.The acceleration behaviour of the car is (dv/dt)=1.22-0.015v,whereby v=speed in m/s,calculate a)maximum speed ...
59 views

### What is the difference between accelerating and boosting?

My professor claimed in class that there was a difference between an acceleration and a boost. I don't really understand the distinction. If you want to go to a different inertial frame of reference, ...
5k views

### Why is 7 TeV considered as a big amount of energy?

Considering that $7$ TeV is more or less the same kinetic energy as a mosquito flying, why is it considered to be a great amount of energy at the LHC? I mean, a giant particle accelerator that can ...
63 views

### Kinetic energy of a rotating object

in an exercise, a linear molecule is being subject to a force applied on the edge in its axis. Then $K_1=\frac{1}{2}mv^2$, all is well. Then in the second point of the exercise, the force is applied ...
34 views

### The Intersection of two periodic bullets at different speed?

I'm trying to find the mathematical equation or concept to calculate an intersection of two bullets at different speed. So basically it's like an intersection of two lines, but I'm trying to add time ...
15 views

45 views

### Is the Coriolis acceleration formula just an approximation?

The Coriolis acceleration given in textbooks is: $a_{cor} = -2\omega v$ When trying to understand the derivation, it seems as though this is just an approximation. And to illustrate this I give a ...
49 views

### Can I call the component of tangential acceleration towards center of circle as the centripetal acceleration?

In my textbook the definition for centripetal acceleration is given, "The acceleration produced by virtue of change in velocity direction is centripetal acceleration" This definition is irritating. ...
76 views

### At a fixed inital velocity, What throwing angle will give the projectile the most trajectory length? [closed]

This is a diagram of a projectile motion: Given a constant initial velocity, What angle gives the most trajectory length? By length I mean the length of the parabola from the point the ball is shot ...
157 views

### Is there mechanical strain on a wire along the direction of current flow?

The (attractive) magnetic force on two parallel wires can be seen by the two wires bending towards each other. This can be explained by the Lorentz force acting on the charges and the charges ...
56 views

### Inclined plane problem [closed]

This is the problem question from my textbook. My questions are concerning some formulas related to this problem. The force of friction is obviously down the plane. My initial question is: ...
331 views

### Velocity time graph for a ball thrown vertically upwards and falling back down to be caught again by a person

I am currently studying AS level physics and having some difficulty understanding the shape of a velocity time graph that represents the motion of a ball being thrown upwards and falling back down to ...
53 views

### For an object in circular motion, does speed affect the amplitude of sound it creates? [closed]

First of all, I'm sorry if this is a stupid question and I've missed something obvious. I used to have an instrument that was a small drum tied to a piece of wood. When you hold the wood and swing the ...
95 views

### Intercept of 2 moving objects at constant acceleration

I have to make a simulation in which a guided missile has to hit an incoming enemy missile.The enemy missile "T" is the one which has to be intercepted and is only affected by gravity, the guided ...
73 views

### What is the meaning of the integral of position?

Jerk, $j(t)=\dddot x(t)$, acceleration, $a(t)=\ddot x(t)$ and velocity, $v(t)=\dot x(t)$ are derivatives of position, $x(t)$. What is the meaning of the integral of position? For example, one could ...
27 views

### Air resistance and computing the maximum height

How do we compute the height of a ball when the velocity with which it was thrown up and the velocity with which it returned to my hand is given. The velocity with which it was thrown and with which ...
194 views

### Projectile motion - calculate landing angle

A projectile is launched at a $45^\circ$ angle, aiming for a target at a distance of 15 feet away from, and $2$ feet below the starting position. I'm looking for equations to determine: The ...
98 views

### Deriving the equation of motion for a rigid system

I want to derive equation of motion for the system shown in picture. How do I choose a generalized coordinate in order to calculate kinetic and potential energy of the system? I need the ...
44 views

### Velocity-time-distance problem

In my book the formula for the $y$-component of velocity during the upward projectile motion is given: $$V_y=V_{iy}-gt$$ and next to it the formula for $y$-component of velocity during the downward ...
27 views

### What affects the motion of a projectile? [closed]

I love physics, and I am recently getting started to know a lot about physics. I won't deny though that I am pretty knew on the subjects, so things such as drag, and external ballistics are foreign to ...
108 views

### Force required to send ball in set trajectory

If I have a desired 2D trajectory where I know the desired speed of my ball and desired path, and a ball that starts at (x=0,y=0), how can I calculate the required force / point at which the force ...