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.

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15 views

Vector and motion in 2D [on hold]

Q. A particle is moving in a circle of radius r centre at O with constant speed v the change in velocity moving from A to B ( angle AOB = 40°) is : A. 2v cos40° B. 2v sin40° C. 2v cos20° D. 2v sin20° ...
1
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2answers
81 views

Computing distance traveled from jerk

When dealing with higher time derivatives like jerk, how does one find the distance traveled? Can it be calculated by just knowing time?
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1answer
3k views

Finding the point of collision between two objects when acceleration is constant

$\newcommand{\accunit}{\mathrm{m}/\mathrm{s}^2}$ A coin is dropped 60.0m above the top of an elevator car. The coin is dropped just as the car begins to move upwards. The elevator first ...
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6answers
743 views

Why is momentum conserved (or rather what makes an object carry on moving infinitely)?

I know this is an incredibly simple question, but I am trying to find a very simple explanation to this other than the simple logic that energy is conserved when two items impact and bounce off each ...
0
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0answers
22 views

Why does kinetic energy quadruple when speed doubles? [duplicate]

Why does kinetic energy quadruple when speed doubles? Please explain (in simple terms) with examples if possible.
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0answers
4 views

Drag coefficient of a rectangular prism

How do you find the drag coefficient, specifically for a rectangular prism-shaped body? What other factors must be taken into consideration when calculating this value?
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1answer
18 views

Finding average acceleration of objects sliding down an inclined plane [on hold]

A toy car of 500g rolls down 1 meter of a 30° plane in 2 seconds. a) The car is a rectangular prism of 10cm x 8cm x 16cm (Width/Height/Depth). What is its average acceleration? b) The car now has a ...
0
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1answer
181 views

Circular motion - is average velocity enough to tell?

If I knew the exact value of constant centripetal force and the average velocity of an object travelling around a circle for time $t$, would that be enough information to determine the final positon ...
2
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1answer
129 views

Am I right in my understanding of angular motion?

Here is what I've understood about angular motion: If a force is applied at the center of mass of a rigid body, it will undergo pure translational motion. If a force is applied away from the center ...
1
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2answers
38 views

How to get these SUVAT formulae?

When learning kinematics, I have learned these three formulae $s=1/2(u+v)t$ $s=ut+1/2at^2$ $v^2=u^2+2as$ s = displacement u = initial velocity v = final velocity t = time a = acceleration My ...
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1answer
18 views

Description of the motion of a charged particle attached to a spring [on hold]

A particle with mass $m$ and charge $q$ move in the $xy$ plane and is attached to an ideal spring with neglectable mass, a spring constant $k$, rest length $r_0$ and a magnetic field $B = B_0z$ is ...
1
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1answer
65 views

What is the meaning or purpose of inertial motions

It seems to me that, except for light, inertial motion is never possible in real world where there is gravity everywhere. It is at best some kind of idealization. But why inertial motions are so ...
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1answer
41 views

Can anyone explain this formula graphically?

$$v^2=u^2+2as$$ v=final velocity; u=initial velocity, a=acceleration; s=displacement. I know and understand how this equation is derived.But, can anyone show me that $v^2=u^2+2as$ using graphic ...
0
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1answer
25 views

Why is parallel component of velocity along position vector considered rate of change of position?

If you have a position vector and a velocity vector of a particle, then the component of velocity vector along position vector is the rate of change of distance of the particle from the reference ...
-1
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0answers
16 views

Meriam dynamics solution manual kinematics [on hold]

I was browsing through the solution of meriam dynamics 6th edition question 2/143 and the answer I found was positive but the solution is negative. Is there some concept I am missing in the problem ...
7
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4answers
2k views

Does a truck stop faster if the stack on the back of truck is stable or if it moves forward?

My question in the title might not be very descriptive so I am re-writing it here: If there is a truck in motion and it has stack of hay (lets suppose) on the back. Now if the truck comes to a sudden ...
0
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1answer
82 views

Inclined plane, circular motion and the friction

Suppose we have a cylinder on an inclined plane of mass $m$ and radius $R$ moving without sliding (so that $\varepsilon = a/R$). Why is the friction $F$ causing the circular motion sometimes lower ...
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2answers
67 views

can kinetic energy be independent of mass.?

Why is it said that the kinetic energy acquired by a body of after traveling a fixed distance from rest under the action of constant force is independent of mass? Nd yeah the mass of the body is ...
3
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2answers
113 views

Submarine Speed Detection [on hold]

A submarine can use sonar (sound traveling through water) to determine its distance from other objects. The time between the emission of a sound pulse (a “ping”) and the detection of its echo can be ...
0
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2answers
34 views

will the acceleration of a freely falling body having rotional motion be differet from g?

A disk is falling freely vertically rotating on its on axis while doing so. Will the acceleration of the body be different from 'g'?
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0answers
45 views

How to find the height where the collision of two balls occurs? [closed]

There was this question that got deleted (for whatever reason): Ball A is dropped from the top of a building of height h at the same instant that ball B is thrown vertically upward from the ...
5
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2answers
478 views

Inertia Vs Momentum

At my recent lesson on kinematics, my teacher taught about inertia and momentum. This is what she said. Inertia: a characteristic of an object that resists changes to its state of motion. Momentum: ...
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0answers
52 views

When and who by was the earliest definition of speed? [migrated]

Speed is defined to be distance divided by time; when and who by was this definition first put forward? The obvious guess would be for Galileo in early modern physics; is this right, and can it be ...
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1answer
63 views

Two equations for $y$ in projectile motions

I have two equations on my equation sheet: $$y=v_o t \sin \theta - \frac{1}{2} g t^2.$$ $$y_{\max} = \frac{v_o^2 \sin^2\theta }{2g}.$$ I understand that the first one is an equation for the height ...
0
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1answer
52 views

How to calculate angular velocity given constant tangential acceleration? [closed]

A car starts moving in a circle with a radius of $200 \text{ m}$. It has a constant tangential acceleration of $1{\text{m}\over {\text{s}}^{2}}$. a. What is the angular acceleration? b. What is the ...
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1answer
696 views

1D Kinematics - Relative Motion involving non-inertial frames of reference

I recently came across a question involving non-inertial frames of reference. I didn't quite understand the way it had been solved due to some conceptual confusion regarding certain deductions made to ...
0
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1answer
133 views

Finding the total energy in centre of mass frame

I'm working through a problem in a special relativity textbook (Woodhouse) and I'm having some difficulty. I have to show that if I have a particle of rest mass $M$, total energy $E$ colliding with a ...
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0answers
22 views

Help with inclined slope motion? [closed]

I have this question (5ii) and I was wondering why this wouldn't work, why can't I solve for acceleration using $v^{2}-u^{2}/2s$=$a$ then solve for $t$? I obviously have to resolve and use $p=fv$ but ...
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1answer
257 views

Tangential and radial acceleration in projectile motion

I'm currently learing kinematics, specifically projectile motion and as an example in my textbook is a bullet fired at some angle. I understand the derivation of formulas to describe that motion and ...
5
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5answers
365 views

Infinite series of derivatives of position when starting from rest

Suppose you have an object with zero for the value of all the derivatives of position. In order to get the object moving you would need to increase the value of the velocity from zero to some finite ...
0
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1answer
29 views

Computing Acceleration in mass and pulley system using conservation of energy

I have a question in which a multiple pulley and mass system is being analysed. I can compute accelerations and Tension without any issue using newtons second law. However I am asked to use ...
3
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3answers
68 views

Does my (too low) tire pressure, affect the speedometer of my car?

Does my (too low) tire pressure, affect the speedometer of my car? How big is this effect?
3
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1answer
254 views

Acceleration: A ball sliding down the inside of a semicircular bowl

Edit: To clarify, this is a homework question. But I couldn't care less about getting the answer to this specific question as it's not even assigned yet. It looks interesting and I want to understand ...
41
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5answers
14k views

How effective is speeding?

At a simple level, speeding in a car attempts to minimize the time required to travel a distance by utilizing the basic relationship: $$d=st$$ So for a given distance, time should be inversely ...
1
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1answer
36 views

What is the position as a function of time for a mass falling down a cycloid curve?

In the brachistochrone problem and in the tautochrone problem it is easy to see that a cycloid is the curve that satisfies both problems. If we consider $x$ the horizontal axis and $y$ the vertical ...
7
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1answer
265 views

Is it possible to determine particles' velocities from their crossings on a ring?

2 particles are constrained to move in a ring. Both particles begin moving at $t=0$ from $p=0$, each particle moving in the opposite direction of the other. It is known that they are moving at ...
0
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1answer
32 views

Six particles at the corners of a regular hexagon of side $a$ move at a constant speed $v$ [duplicate]

Each particle maintains a direction towards the particle at the next corner. Calculate the time the particles will take to meet each other. When the particles move with same speed,how can they ever ...
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2answers
13 views

Net Force On An Object

If 5 different forces are acting on an object in the same direction, is it possible for the net force to equal 0? Could Friction or Gravity make this possible? If so then how?
2
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3answers
494 views

Object moving in a circular path without accelerating

A train is moving with a constant speed on a straight portion of track. Then, it encounters a curve in the tracks, and goes along the curve. However, it does not change the magnitude of acceleration ...
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2answers
32 views

What theories or formulas are involved with velocity

What theories or formulas are involved or can be added as background information in an experiment that sees a small toy car roll freely down an incline where the surface area is altered to cause more ...
0
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1answer
37 views

Kinematics - When projectile lands at an angle

Question: You are watching an archery tournament when you start wondering how fast an arrow is shot from the bow. Remembering your physics, you ask one of the archers to shoot an arrow parallel to ...
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1answer
85 views

What factors affect the velocity of an object moving down an inclined plane?

If you have a small toy car rolling down an wooden plank, what factors would increase or decrease the velocity of said car. In the experiment my team originally stated that adding mass to the car ...
0
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3answers
43 views

How does $p=fv$ hold when $v=0$ and an engine is working?

Standard high school equations: Work = Force x Distance Power = Work / Time = Force x Distance / Time = Force x Velocity When a space rocket takes ...
3
votes
2answers
816 views

How can an object move from point A to point B?

If I was at point $A$ and I wanted to walk directly to point $B$, I would have to walk half way to point $B$, but before that I would have to walk half way to halfway to halfway to point $B$ and half ...
0
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2answers
2k views

Homework Question Transformation Energy [closed]

A $1400kg$ car is approaching the hill shown in the figure at $14.0m/s$ when it suddenly runs out of gas. What is the car's speed after coasting down the other side? I think I have to use this ...
0
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1answer
84 views

How does angular momentum affect the trajectory of a projectile?

I am thinking about a football thrown in a very tight, very fast spinning spiral. If the football is thrown upwards at a high angle, is it possible for the football to not turn over at the top of its ...
1
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1answer
92 views

Magnitude of the average velocity vector (not the average speed)

Thank you ahead of time for taking to look at this. For this following problem we were given an answer however I am almost positive the given answer is wrong. It doesn't even make sense. So here is ...
1
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1answer
214 views

Shooting a bullet at a system of blocks [closed]

So, I made this question up myself.... and I'm curious about the answer. It requires only secondary-school-level knowledge of physics: You have a surface (ground) with a certain coefficient of ...
0
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2answers
156 views

Ball flying towards me - Newton's third law is violated?

I was trying to answer the question of the flying ball here on the basis of Newtons third law and Momentum conservation. Here is what I have tried. Lets take $m_1$ (the ball) hits $m_2$ (the man). ...
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1answer
38 views

Maximum Momentum of Neutral Pion

I'm considering the reaction $p + p \rightarrow p + p + \pi^0$. To find the maximum momentum that the $\pi^0$ can have after this reaction in the center-of-mass frame, what I am doing is assuming the ...