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.

learn more… | top users | synonyms (2)

1
vote
1answer
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 ...
1
vote
0answers
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 ...
1
vote
0answers
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 ...
0
votes
1answer
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 ...
0
votes
1answer
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, ...
-1
votes
1answer
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 ...
-1
votes
1answer
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?
0
votes
0answers
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 ...
1
vote
1answer
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 ...
0
votes
3answers
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, ...
35
votes
4answers
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 ...
2
votes
3answers
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 ...
0
votes
1answer
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 ...
1
vote
0answers
15 views

Relativistic particle decay in ZMF [closed]

This is a problem that I feel is harder than I am making it but say you have: A particle at rest of mass $M$ decays into two smaller particles of masses $m_1, m_2$ where $m_1 \neq m_2$ and $M > ...
1
vote
0answers
51 views

Which Method for finding velocity of an object in the mirror is correct? [closed]

My Professor asked a question, "A person is seen jogging in a rear view mirror of focal length $1$m. He is at a distance $39$m from the mirror. His jogging speed is given to be $5 \frac{m}{s}$. ...
1
vote
1answer
36 views

Point rolling on a ball [duplicate]

Assume we are provided with a perfectly spherical and frictionless ball of radius R. A point is placed on the top of the ball. A velocity u is imparted on the ball to one side of the ball. How can we ...
1
vote
0answers
25 views

How does Initial velocity effect braking distance? [closed]

supposed we have a car that slams the brake to bring it to stop, how would doubling it's mass affect braking distance and how would halving its velocity affect it? I used the equation d=Vi^2/2×a
5
votes
1answer
53 views

Will the speed of the wind produced by a fan increase continously to infinity with the propeller spin speed?

Imagine a scenario: On a stand, an $RC$ plane motor is mounted on a stand. The motor has a $8x4$ prop attached to it. In the theoretical model, if the spin of the motor can be increased infinitely ...
1
vote
1answer
46 views

2D - What is the next point given a start point, velocity, yaw rate, acceleration, and time change?

In a two-dimensional environment: Given: a starting point (x1,y1) an initial velocity (speed and 2D heading/direction) a constant rate of turning (yaw, since there is no roll or pitch in only two ...
1
vote
1answer
109 views

In perfect vacuum (no external force), if I apply a small amount of force to a body, will it continue to accelerate forever?

According to the equation F = ma, the greater the force applied to a body, the more is it's acceleration. But in a place where there is no gravity or any other kind of external force, If I apply a ...
0
votes
2answers
45 views

Why the distance equation is not working while calculating distance manually?

I was wondering how the average velocity is the arithmetic mean of initial velocity and final velocity if acceleration is constant. So, my first part of the question: Can someone give me an algebraic ...
1
vote
0answers
38 views

Calculating torque needed to climb a graded hill [closed]

this is my first post but I'll try to give my best understanding of the problem. I've been designing an electric skateboard which is driven by only one of the rear wheels (for the moment). As I was ...
5
votes
1answer
175 views

Why does a stream of water behave like this when aimed against a spoon or into a glass?

I noticed while doing everything except the dishes that water behaves quite strange. These two things might be two different phenomenon, but the water acts in a similar way in both cases. Spoon and ...
1
vote
2answers
59 views

Period of mass in circular motion [closed]

I've been trying for 4 days now to solve my physics lab assignment but now I'm starting to think there must be a mistake in the question. You know those rotating mass experiments where you have a mass ...
2
votes
1answer
196 views

Automobile Air bags [closed]

This is a problem that has many answers on google but I don't understand what is the underlying logic of the steps taken. Here's the problem The human body can survive an acceleration trauma ...
0
votes
2answers
57 views

Is the Earth's molten outer core affecting its motion?

According with the seismological studies [1] the outer core, with thickness of about $2300km$, starting from depth of $2,900 km$ and ending at $5,200 km$ is a low viscosity fluid, consisted mostly of ...
0
votes
0answers
48 views

Correct formulas for two wheeled robot motion

I'm trying to write a simulation of a two wheeled robot, which can be controlled by varying the speeds of his wheels, independently. However, the physics engine that I'm using can only rotate a body ...
1
vote
0answers
26 views

Relativity collision problem [closed]

Here is the problem: A body of mass m (I assumed this is rest mass, but not 100%), and momentum p(subscript m) collides with a stationary particle of mass M. Find the available energy in the CM ...
0
votes
3answers
41 views

What numbers do we examine when predicting how much damage an object will do when it strikes another object?

A 1,000 pound boulder at rest is pushed with a constant acceleration for 6 seconds, causing it to move 30 feet. It then strikes a medieval castle wall made of stone and mortar. If we know nothing more ...
1
vote
0answers
57 views

Kinematics question. A falling object falls [closed]

This is quite bad for me as I'm a third year physics student now, however I'm attempting to go back on my old first year work as a refresher, but I'm completely stuck on a question! Can anyone help? ...
0
votes
2answers
25 views

Confusion regarding resolution of forces

I'm looking at a basic free body diagram of a car travelling on a banked(inclined) road with inclination theta. It's mass is 'm'. Here the diagram shows weight (mg), Normal reaction(N), and ...
0
votes
1answer
47 views

Acceleration in Space

Lets assume a body with a certain mass is in a region of space that has zero $g$ (or pretty close to zero $g$). Would acceleration in a straight line produce $g$-forces? Would that mass acquire ...
-1
votes
1answer
40 views

Unit Vector Displacement [closed]

A particle starts from the origin at $t = 0$ with a velocity of $+4.0\mathbf{j} \text{ m/s}$ and moves in the $xy$ plane with a constant acceleration of $(6.0\mathbf{i} + 4.0\mathbf{j}) \text{ ...
0
votes
1answer
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 ...
0
votes
1answer
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. ...
1
vote
1answer
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 ...
6
votes
1answer
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 ...
0
votes
1answer
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: ...
0
votes
2answers
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 ...
2
votes
1answer
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 ...
0
votes
2answers
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 ...
1
vote
1answer
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 ...
0
votes
1answer
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 ...
1
vote
2answers
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 ...
0
votes
1answer
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 ...
0
votes
1answer
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 ...
1
vote
0answers
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 ...
1
vote
4answers
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 ...
0
votes
0answers
53 views

How to calculate the equations of motion for a dipole in an electric field in three dimensions

I'm having trouble modelling a system, which I thought would be simple but has turned out to be quite complicated. The system is a charged sphere in an oscillating three dimensional electric field. ...
0
votes
2answers
103 views

Spring and pendulum massive bob trajectory? [closed]

This is essentially a better formatted version of this question which was put on hold (also by myself), mainly for being a HW&E question without any research effort by the OP and poor formatting. ...