What is Kinematic: Definition and 406 Discussions

Kinematics is a subfield of physics, developed in classical mechanics, that describes the motion of points, bodies (objects), and systems of bodies (groups of objects) without considering the forces that cause them to move. Kinematics, as a field of study, is often referred to as the "geometry of motion" and is occasionally seen as a branch of mathematics. A kinematics problem begins by describing the geometry of the system and declaring the initial conditions of any known values of position, velocity and/or acceleration of points within the system. Then, using arguments from geometry, the position, velocity and acceleration of any unknown parts of the system can be determined. The study of how forces act on bodies falls within kinetics, not kinematics. For further details, see analytical dynamics.
Kinematics is used in astrophysics to describe the motion of celestial bodies and collections of such bodies. In mechanical engineering, robotics, and biomechanics kinematics is used to describe the motion of systems composed of joined parts (multi-link systems) such as an engine, a robotic arm or the human skeleton.
Geometric transformations, also called rigid transformations, are used to describe the movement of components in a mechanical system, simplifying the derivation of the equations of motion. They are also central to dynamic analysis.
Kinematic analysis is the process of measuring the kinematic quantities used to describe motion. In engineering, for instance, kinematic analysis may be used to find the range of movement for a given mechanism and working in reverse, using kinematic synthesis to design a mechanism for a desired range of motion. In addition, kinematics applies algebraic geometry to the study of the mechanical advantage of a mechanical system or mechanism.

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1. Engineering Problem calculating the force on a tube wall

A-A' (mv1^2)/2-(mv0^2)/2 = A A = -AG + AT - AF AG = mgh = 1.47 J AT = k/2*h0^2 = 0.0125 J AF = fmg*cos(60)*h0 = 0.0735 J A = -AG*cos(30) + AT - AF = -1.334 A-C (mv1^2)/2-(mv0^2)/2 = A A = AG C NC + Gcos(45) - Φn = 0

32. Hard kinematics problem: Block pushed onto a moving conveyor belt

stuck on this question
33. Maximum Distance a Projectile Moves Up an Inclined Plane

the red line is the initial velocity, the grey parabola is the path of the projectile. hi there...I'm kinda stuck at the part b of this problem. I can do part a with no problem. can anybody explain to me how to do the differentiation needed to solve part b?? by explain I mean explain the...
34. Engineering Kinematic and geometric similarity (fluids)

My attempt at a solution is to start off first denoting V_a to be the automobile an V_e to be the economy version. Same goes with l_a and l_e. To try and relate the two I have tried: V_a I_a = V_l L_e, however I am really not sure how they got the square root. The answer is: v = V sqrt(l/L)...
35. Kinematics Problem: constant acceleration, motion in a line

I've been attempting to solve this problem for three days now. I have thrown away my old attempts (like, scrumpled up into the bin), but my old attempts involved: Trying to set up simultaeneous equations relating the journeys between EH and FG to find the deceleration, but the reason why this...
36. Issac Physics 'Three Collisions' High School Homework - Kinematic

Homework Statement: Three particles A, B, and C, each of mass 𝑚, lie at rest in that order in a straight line on a smooth horizontal table. The particle A is then projected directly towards B with speed 𝑢. The masses of A, B, and C are now 𝑚, 2𝑚 and 3𝑚 respectively: Again find the fraction of...
37. Kinematic in Quadratic Form Equation (missing something simple)

I just ran this pretty quick at work. But this is the general outline. Sorry for the slop, it will get better with time. Thanks in advance and any additional info can be supplied. The material is from the Khan free course. ..... A student is fed up with doing her kinematic formula homework...
38. Kinematic Equations: Find the time t when two objects meet

Part A) So, I set the two positions equations of A and B equal to each other since the position has to be the same. A: 0 + 0 + 1/2(2)t^2 = 50 + 0 + 1/2(4)t^2 :B I know I have to solve for time t, but there's no way to solve it with both sides having t^2 so I am not sure which variables I got...
39. Doubts on the sign of acceleration

What should I do? Because I have two possibilities. I have ##0=5+at## so ##-5/t =a##. But then I can also say that the acceleration is a negative because it is stopping, so I can write it like ##0=5-kt## and then ##5/t =k##

41. Relative rotational motion on a disc

The first doubt that comes to my mind is "I have to determine the acceleration with respect to what?", because the problem doesn't tell. Then, I have some problems when having to plug the data in the formula of acceleration. ##\vec a_B=0## because the origin isn't accelerated, ##\vec{\dot...

47. Airtime for halfpipe skateboarder

I've calculated the potential energy at the top of the halfpipe, before the boarder drops in: PE = 39.5 kg * 9.8 m/s^2 * 3.66 m = 1416 J Since the boarder would have no potential energy and all kinetic energy at the bottom of the halfpipe, KE = 1/2mv^2 = 1416 J 1/2 (39.5 kg) (v^2) = 1416 J So...

49. Man on ladder: jump off instantly vs last moment?

So there are two cases: a). free fall (straight forward for me) b). ladder rotating and jumping off in last moment (I am interested in trying to understand this case) I believe I should take into account momentum at the time the man hits the ground in both cases? The smaller, the better. Or...
50. How can I calculate the acceleration of a baseball thrown by a pitcher?

Hello. I have just started studying physics. Can someone explain to me how can I type in formulas here using Tex for nicer formatting? I suppose the force is F = ma. Question is: what is a? The starting throw angle is not mentioned, I suppose this task has to be related to gravity. All I know...