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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2answers
56 views

How to determine the net velocity change applied by a force vector [closed]

I am a little stumped by the answer of this question. The question reads, "In three situations, a single force acts on a moving particle. Here are the velocities (at that instant) and the forces: ...
2
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1answer
99 views

Why can't I use conservation of energy to find ratio of final velocities on different planets?

The question is An object of mass $m$ is allowed to slide down a frictionless ramp of angle $\theta$, and its speed at the bottom is recorded as v. If this same process was followed on a planet ...
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0answers
31 views

Helicity of massive particle at high enengy

We know that massless spin-1 particle like photon only has two helicity state (-1,1), what about the helicity of massive spin-1 particle (W boson) at very high energy? Does it have helicity 0 state ...
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2answers
70 views

Finding acceleration due to gravity of a 2D projectile

Can I find acceleration due to gravity of a 2D projectile given only the peak of the projectile, the point of impact, initial angle, and initial velocity? Specifically what is missing is the initial ...
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2answers
51 views

Does the position-time graph have to be a smooth function?

If at some time $t$ there were a discontinuity in the velocity-time graph, then the acceleration would be infinite at $t$. So intuitively, it seems that the velocity-time graph must be continuous. I ...
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1answer
64 views

Olympiad problem - struggling with polar coordinates [closed]

This is a physics olympiad problem; and I am still struggling with it. I will quote it here: " A particle moves along a horizontal track following the trajectory $r=r_{0}e^{-k\theta}$, where $\theta$ ...
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0answers
21 views

Kinetic energy vs Kinetic Energy scenario in a collision, mechanical energy used for work?

Most collisions have Kinetic energy conserved or in the case of inelastic collisions energy is lost into other forms. Though the equation of "TMEi + Wnc =TMEf" is true however, what if two unequal ...
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2answers
50 views

Why do I get two different answers? Using Calculus and Using Newton for Distance/Velocity [closed]

Why do I get two different answers? QUESTION: How long does it take to slow down from 8000 m/s to 6000 m/s with an acceleration of -400 m/s^2 ? GIVENS D distance V velocity T time V initial ...
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3answers
51 views

Why the similarity in the Equations of Motion for Rotational and Rectilinear Motion?

These are the equations of motion given constant acceleration, for first rectilinear and then rotational motion. Rectilinear Motion: Rotational Motion: While the variables have changed, and the ...
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1answer
51 views

Homework: Expression for minimum speed to cause collision of objects / simple kinematics

I have a question which is worded as follows: Person A throws a rock at a 45∘ angle to the horizontal, aiming at Person B who's standing on a building at heigh h above level ground. At the ...
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0answers
50 views

What kind of unit is $m^2s^{-4}$ in terms of gyro/accel?

Background While working on something in the field of avionics, I have discovered the following unit as part of an inertial-physics equation... $$m^2s^{-4}$$ I am trying to figure out the formal ...
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2answers
53 views

How can I find the maximum height if I have changing acceleration?

I'd like to find the maximum height that a projectile reaches in motion if I have a non-constant acceleration. How would I do this? What variables do I need to know in order to calculate this? ...
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1answer
54 views

Instantaneous Velocity after bouncing off a wall

I have a ball, and I throw it at a wall as a projectile (assume that the ball's position the instant the journey begins is on level-ground). The ball hits the wall with a velocity that is at right ...
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1answer
32 views

What decides distribution of momenta and energy in rigid collisions?

I recall in Highschool physics receiving a problem of the form "assume 2 spherical bodies" $P_1, P_2$ enter a collision where $P_1$ has momentum $m_1 V_1$ and $P_2$ has momentum $m_2 V_2$, both ...
2
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2answers
122 views

Explicit Function for Bouncing Ball [closed]

I was wondering if it's possible (and if so, how would you go about it) to write an explicit function for the position of a ball bouncing as a function of time (assuming a coefficient of restitution 0 ...
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0answers
9 views

Kinematics:homework question [duplicate]

Q.)A particle goes along a quadrant AB of a circle of radius 5cm with a constant speed of 2.5cm/s as shown.Find the average velocity. Attempt at the solution: 1.I calculated the displacement between ...
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0answers
9 views

Why the two different methods yield different answer in kinematics [duplicate]

Q.)A particle goes along a quadrant AB of a circle of radius 5cm with a constant speed of 2.5cm/s as shown.Find the average velocity. Attempt at the solution: 1.I calculated the displacement between ...
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0answers
31 views

Kinematics - Non constant acceleration [closed]

A biker traveling the road is 100 km away from his destination, at t=0 (initial time). His speed, at the start point, is 100km/hour, and varies equalys to his distance from the final destination, ...
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0answers
25 views

How to find out radius of curvature by knowing velocity and angle with horizontal of a body [closed]

A particle moving in air with initial velocity 100 m/s making an angle 60 degree with horizontal then how to calculate radius of curvature at time equals to one second ??
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0answers
34 views

Circular motion and car tire angle [closed]

I'm trying to figure out what angle to turn the front tires of my small robotic car (about a foot in length) so that it moves in a circle (on level ground) of radius r (will be accommodating circles ...
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1answer
62 views

what is the energy required to change only direction of a vector? [closed]

Does change in velocity vector change Kinetic energy of a system? Does any energy change when we change direction of a vector of a system?
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0answers
35 views

graphical representation of Maxwell velocity distribution law

I have read Maxwell's distribution law it is the probabilistic representation of no. Of particles having velocity between $c$ to $c+DC$,through this representatation we can get the number of particle ...
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1answer
21 views

Calculate the height reached when 1/3 of original Kinetic Energy is lost [closed]

I am sorry for asking this low level question but there is a confusion, I am not overcoming from hours. My book asks me to solve the following problem: When an object is thrown upward, it rises ...
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0answers
31 views

Relation between linear and rotational motion of molecules?

The temperature of a substance, such as an ideal gas, can be related to the root mean square speed of the molecules. For example, for gases the molecules travel at about 480 meters per second. If we ...
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2answers
63 views

Why do tops move opposite to each other when colliding, not tangentially?

When two well-balanced tops collide, they tend to bounce directly away from each, in other words along the line connecting their centers. Intuitively I would expect the tops to move tangentially, not ...
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2answers
77 views

The force causing galaxies to accelerate away from each other?

The galaxies in the universe appear to be accelerating away from each other according to the Doppler shift that is present in the light we receive from other galaxies. According to Newtonian ...
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1answer
169 views

Projectile time of ascent not equal to the time of descent?

Why is the time of ascent less than the time of descent in a projectile motion. I understand that while going up the air resistance and gravity act downwards and while coming down gravity is ...
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1answer
51 views

Uncertainty in Range of Projectile [closed]

If we are given that a projectile is launched with velocity 10m/s at an angle of $45^\circ$ and uncertainty in angle is of $0.5^\circ$ . What is the uncertainty in the range of projectile. The problem ...
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2answers
67 views

Free falling and bouncing back

My confusion arises with free falling body. For a free falling body the displacement ~ time graph has a kink (at the time when the body hit the ground ). at a kink point, a function is not ...
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0answers
47 views

About the formula of pendulum simple

for the modulation and the simulation of a pendulum simple , I'm Find this formula : a(t) = a0 * sin ( sqrt(g/l) * t * Pi/2 ) - [ k/(mll) * cos ( sqrt(g/l) * t * Pi/2 ) * t ) ] ...
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1answer
72 views

Simultaneous translation and rotation

I would like to describe the motion of a particle in a rigid body by introducing 6 degrees of freedom which are three translational dofs ($u,v,w$ ) in fixed coordinate system $R_0$($X,Y,Z$) and three ...
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1answer
32 views

Force required to produce a specific motion on a particle [closed]

This exercise comes from the Exercises for the Feynman Lectures, Chapter 15. The full question: 15-6 A particle of rest mass $m_0$ is caused to move along a line such that its position is: ...
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0answers
6 views

Average velocity formulas [duplicate]

Total distance/time taken and (Vi+Vf)/2 are both refered to as formulas for average velocity. What is the difference and similarity between these two?
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1answer
77 views

How does friction affect the motion of a pendulum?

I would like to know what is the difference in the equation of motion of a pendulum in the presence or the absence of frictional forces. And how this translates to the solution of those equations?
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1answer
22 views

Do you use static or kinetic friction when calculating this problem?

You are given mass and initial velocity of a vehicle and told that you need to stop. You are given kinetic and static friction and asked to find the minimum distance. Would you use kinetic friction or ...
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3answers
129 views

Can there be motion without the flowing of time? [closed]

tldr - Can we reject the notion of the passage of time, but still accept that motion is real? This question is a follow up to comments between myself and the author of this answer to the question, ...
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1answer
30 views

question from the idea of relative acceleration [closed]

the accelerations of a particle as seen from two frames $S_1$ and $S_2$ have equal magnitude $4 m/s^2$ so my teacher said that the acceleration of $S_2$ with respect to $S_1$ may be anything between ...
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4answers
66 views

For a particle moving in a straight line

If the velocity is zero for a time interval, is the acceleration zero at any instant within the time interval ?
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1answer
55 views

Energy and Momentum: Impact

Boat A has just lost another race to Boat B. In a fit of rage, the driver of Boat A (mass = 500 kg) turns his boat towards Boat B (mass = 450 kg) which is at rest as the driver gloats over yet another ...
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2answers
48 views

Regarding Basic laws of motion

When a constant force is applied on body which is free to slide on a surface, does it move with a constant velocity after some time or does the velocity keep on increasing? Please explain it for both ...
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2answers
24 views

Why do the following two constant acceleration equations produce contradicting outputs?

Let acceleration = -a. I'm was originally trying to find the stopping distance in terms of $v_0$ and $a$ Two relevant equations of linear motion with constant acceleration then become $x = \frac12(-...
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0answers
29 views

Direction of motion 1 [closed]

A man on a bike travelling east on straight road at 8km/h sees a car driving north at 60km/h. What is the apparent speed and diretion of motion of car to the cyclist?
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1answer
39 views

What will happen if you move a photon move in a straight line with no oscillations? [closed]

As light is a wave, it travels in an oscillating pattern: | _ _ _ _ _ _ _ _ |/_\ _ /_\___/_\ _ /_\___/_\ _ /_\___/_\ _ /_\___ | \_/ \_/ \_/ \_/ \_/ \_/ ...
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2answers
48 views

Impulse Equations

A solid sphere of mass $m$ rolls without slipping on a horizontal surface and collides with a vertical wall, elastically. The coefficient of friction between the sphere and wall is $\mu$. After the ...
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1answer
58 views

Impact Speed of a car

A car (Mass 4500 Kg) hits a concrete Block (1000 Kg) on left edge. After impact, block rotates in circular motion and stops at about 24 feet from its initial position. How to calculate force with ...
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2answers
56 views

Free Fall Motion in Physics [closed]

A man in a close elevator with no floor indicator,does not know whether the elevator is stationary, moving upward or moving downward at a constant velocity. To try to find out, the person drops a coin ...
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0answers
41 views

Velocity of an object rolling down a spiral

Imagine a fiction less spring-like spiral, an object will roll down the wire path the spring creates. From conservation of energy, the initial PE will be equivalent to gravitational potential energy, ...
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2answers
63 views

Would this be correct for kinetic energy in special relativity?

In galilean relativity $$p=mv$$ and $$KE=\frac{1}{2}mv^2$$ If I understand it in special relativity the equation for momentum is $$p=\frac{mv}{\sqrt{1-\frac{v^2}{c^2}}}$$ In galilean relativity ...
2
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1answer
45 views

Why are my answers wrong for braking distances? [closed]

I have been working on a presentation to find the braking distances at the velocities of cars obeying speed limits for a range of common speed limits. I'm working with the equation $$d= \frac{v^2}{...
1
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1answer
49 views

Vector Navigation and equations [closed]

So I am taking a grade 12 physics online course and I am getting stuck on the Vector Navigation equations as there isn't much explanation in my course. The following text is found in my online course....