"(metric system) as metres per second (m/s) or as the SI base unit of (m⋅s). For example, ""5 metres per second"" is a scalar, whereas ""5 metres per second east"" is a vector. If there is a change in speed, direction or both, then the object has a changing velocity and is said to be undergoing an ""acceleration"". To have a constant velocity, an object must have a constant speed in a constant direction. Constant direction constrains the object to motion in a straight path thus, a constant velocity means motion in a straight line at a constant speed. For"
"Acceleration In physics, acceleration is the rate of change of velocity of an object with respect to time. An object's acceleration is the net result of all forces acting on the object, as described by Newton's Second Law. The SI unit for acceleration is metre per second squared Accelerations are vector quantities (they have magnitude and direction) and add according to the parallelogram law. The vector of the net force acting on a body has the same direction as the vector of the body's acceleration, and its magnitude is proportional to the magnitude of the acceleration, with the object's mass"
"Particle acceleration In a compressible sound transmission medium - mainly air - air particles get an accelerated motion: the particle acceleration or sound acceleration with the symbol a in metre/second. In acoustics or physics, acceleration (symbol: ""a"") is defined as the rate of change (or time derivative) of velocity. It is thus a vector quantity with dimension length/time. In SI units, this is m/s. To accelerate an object (air particle) is to change its velocity over a period. Acceleration is defined technically as ""the rate of change of velocity of an object with respect to time"" and is given by"
"Planck acceleration The Planck acceleration is the acceleration from zero speed to the speed of light during one Planck time. It is a derived unit in the Planck system of natural units. Planck acceleration may be stated as formula_1 formula_2 formula_3 where a is the Planck acceleration, ""c"" is the speed of light, ""t"" is the Planck time and ""g"" is the standard acceleration of gravity. The Planck acceleration is the highest acceleration conceivable in the Universe, as the speed of light is the highest possible speed and the Planck time is the shortest possible duration of any meaningful physical"
"the acceleration of gravity is 32 feet per second per second and the initial upward speed is 500 feet per second. It is not even necessary for ""t"" to be in ""seconds"". For example, suppose ""t"" = 0.01 minutes. Then the first term would be The value of a dimensional physical quantity ""Z"" is written as the product of a unit [""Z""] within the dimension and a dimensionless numerical factor, ""n"". When like-dimensioned quantities are added or subtracted or compared, it is convenient to express them in consistent units so that the numerical values of these quantities may be directly"
"can be thought of as the second derivative of with respect to : Acceleration has the dimensions of velocity (L/T) divided by time, i.e. L.T. The SI unit of acceleration is the metre per second squared (m s); or ""metre per second per second"", as the velocity in metres per second changes by the acceleration value, every second. An object moving in a circular motion—such as a satellite orbiting the Earth—is accelerating due to the change of direction of motion, although its speed may be constant. In this case it is said to be undergoing ""centripetal"" (directed towards the center)"
"Front velocity In physics, front velocity is the speed at which the first rise of a pulse above zero moves forward. In mathematics, it is used to describe the velocity of a propagating front in the solution of hyperbolic partial differential equation. Associated with propagation of a disturbance are several different velocities. For definiteness, consider an amplitude modulated electromagnetic carrier wave. The phase velocity is the speed of the underlying carrier wave. The group velocity is the speed of the modulation or envelope. Initially it was thought that the group velocity coincided with the speed at which ""information"" traveled. However,"
"Velocity The velocity of an object is the rate of change of its position with respect to a frame of reference, and is a function of time. Velocity is equivalent to a specification of an object's speed and direction of motion (e.g. to the north). Velocity is a fundamental concept in kinematics, the branch of classical mechanics that describes the motion of bodies. Velocity is a physical vector quantity; both magnitude and direction are needed to define it. The scalar absolute value (magnitude) of velocity is called , being a coherent derived unit whose quantity is measured in the SI"
"clock rate and distance measure, and the notion of simultaneity in the direction of motion is altered, so the addition law for velocities is changed. This change is not noticeable at low velocities but as the velocity increases towards the speed of light it becomes important. The addition law is also called a composition law for velocities. For collinear motions, the speed of the object (e.g. a cannonball fired horizontally out to sea) as measured from the ship would be measured by someone standing on the shore and watching the whole scene through a telescope as The composition formula can"
"frequency. The fluctuations are visually quantitated as the amplitude of the peak-to-trough in beats per minute. Using this definition, the baseline FHR variability is categorized by the quantitated amplitude as: The NICHD nomenclature defines an acceleration as a visually apparent abrupt increase in fetal heart rate. An abrupt increase is defined as an increase from the onset of acceleration to the peak in less than or equal to 30 seconds. To be called an acceleration, the peak must be greater than or equal to 15 bpm, and the acceleration must last greater than or equal to 15 seconds from the"
"Angular acceleration Angular acceleration is the rate of change of angular velocity. In three dimensions, it is a pseudovector. In SI units, it is measured in radians per second squared (rad/s), and is usually denoted by the Greek letter alpha (α). The angular acceleration vector is defined as: where formula_2 (omega) is the angular velocity vector. The angular acceleration of a point particle α can be connected to the applied torque τ by the following equation: where ""m"" is the mass of the particle and ""I"" is its moment of inertia. Above relationship indicates that, unlike the relationship between force"
"motion of particle. More mathematically, the rate of change of the position vector of a point, with respect to time is the velocity of the point. Consider the ratio formed by dividing the difference of two positions of a particle by the time interval. This ratio is called the average velocity over that time interval and is defined as Velocity=displacement/time taken where ΔP is the change in the position vector over the time interval Δ""t"". In the limit as the time interval Δ""t"" becomes smaller and smaller, the average velocity becomes the time derivative of the position vector, Thus, velocity"
"Particle velocity Particle velocity is the velocity of a particle (real or imagined) in a medium as it transmits a wave. The SI unit of particle velocity is the metre per second (m/s). In many cases this is a longitudinal wave of pressure as with sound, but it can also be a transverse wave as with the vibration of a taut string. When applied to a sound wave through a medium of a fluid like air, particle velocity would be the physical speed of a parcel of fluid as it moves back and forth in the direction the sound wave"
"and acceleration, the angular acceleration need not be directly proportional or even parallel to the torque. In fact, this is true whenever the moment of inertia of the particle changes with time. Angular acceleration Angular acceleration is the rate of change of angular velocity. In three dimensions, it is a pseudovector. In SI units, it is measured in radians per second squared (rad/s), and is usually denoted by the Greek letter alpha (α). The angular acceleration vector is defined as: where formula_2 (omega) is the angular velocity vector. The angular acceleration of a point particle α can be connected to"
"Jerk (physics) In physics, jerk is the rate of change of acceleration; that is, the time derivative of acceleration, and as such the second derivative of velocity, or the third time derivative of position. According to the result of dimensional analysis of jerk, [length/time], the SI units for its magnitude are m/s (or m⋅s); this can also be expressed in standard gravity per second (""g""/s). Jerk is a vector, and (as with ""acceleration"") there is no distinct term to denote its scalar magnitude (more precisely, its norm, as, e.g., there is ""speed"" for the norm of the velocity vector). Jerk"
"particle. This arc-length traveled by a particle over time is a non-decreasing quantity. Hence, ""ds""/""dt"" is non-negative, which implies that speed is also non-negative. The velocity vector can change in magnitude and in direction or both at once. Hence, the acceleration is the rate of change of the magnitude of the velocity vector plus the rate of change of direction of that vector. The same reasoning used with respect to the position of a particle to define velocity, can be applied to the velocity to define acceleration. The acceleration of a particle is the vector defined by the rate of"
"formula_2. Mathematically, Instantaneous acceleration, meanwhile, is the limit of the average acceleration over an infinitesimal interval of time. In the terms of calculus, instantaneous acceleration is the derivative of the velocity vector with respect to time: It can be seen that the integral of the acceleration function is the velocity function ; that is, the area under the curve of an acceleration vs. time ( vs. ) graph corresponds to velocity. As acceleration is defined as the derivative of velocity, , with respect to time and velocity is defined as the derivative of position, , with respect to time, acceleration"
"acceleration. Proper acceleration, the acceleration of a body relative to a free-fall condition, is measured by an instrument called an accelerometer. In classical mechanics, for a body with constant mass, the (vector) acceleration of the body's center of mass is proportional to the net force vector (i.e. sum of all forces) acting on it (Newton's second law): where F is the net force acting on the body, ""m"" is the mass of the body, and a is the center-of-mass acceleration. As speeds approach the speed of light, relativistic effects become increasingly large. The velocity of a particle moving on a"
"Velocity-addition formula In relativistic physics, a velocity-addition formula is a three-dimensional equation that relates the velocities of objects in different reference frames. Such formulas apply to successive Lorentz transformations, so they also relate different frames. Accompanying velocity addition is a kinematic effect known as Thomas precession, whereby successive non-collinear Lorentz boosts become equivalent to the composition of a rotation of the coordinate system and a boost. Standard applications of velocity-addition formulas include the Doppler shift, Doppler navigation, the aberration of light, and the dragging of light in moving water observed in the 1851 Fizeau experiment. The notation employs as velocity"
"of a line is change in formula_10 over change in formula_11: Where formula_13 is the velocity, measured in formula_14, and formula_3 is the time measured in seconds. This slope therefore defines the average acceleration over the interval, and reducing the interval infinitesimally gives formula_16, the instantaneous acceleration at time formula_3, or the derivative of the velocity with respect to time (or the second derivative of the position with respect to time). The units of this slope or derivative are in meters per second per second (formula_18, usually termed ""meters per second-squared""), and so, therefore, is the acceleration. Since the velocity"
"Rapidity In relativity, rapidity is commonly used as a measure for relativistic velocity. Mathematically, rapidity can be defined as the hyperbolic angle that differentiates two frames of reference in relative motion, each frame being associated with distance and time coordinates. For one-dimensional motion, rapidities are additive whereas velocities must be combined by Einstein's velocity-addition formula. For low speeds, rapidity and velocity are proportional, but for higher velocities, rapidity takes a larger value, the rapidity of light being infinite. Using the inverse hyperbolic function , the rapidity corresponding to velocity is where c is the velocity of light. For low speeds,"
"typically moves at a speed of up to 47 metres per hour. Metre per hour Metre per hour (American spelling: meter per hour) is a metric unit of both speed (scalar) and velocity (Vector (geometry)). Its symbol is m/h or m·h (not to be confused with the imperial unit symbol mph. By definition, an object travelling at a speed of 1 m/h for an hour would move 1 metre. The term is rarely used however as the units of metres per second and kilometres per hour are considered sufficient for the majority of circumstances. Metres per hour can however be"
"Proper velocity In relativity, proper velocity, also known as celerity, is an alternative to velocity for measuring motion. Whereas velocity relative to an observer is distance per unit time where both distance and time are measured by the observer, proper velocity relative to an observer divides observer-measured distance by the time elapsed on the clocks of the traveling object. Proper velocity equals velocity at low speeds. Proper velocity at high speeds, moreover, retains many of the properties that velocity loses in relativity compared with Newtonian theory. For example, proper velocity equals momentum per unit mass at any speed, and therefore"
"velocity of bubbles that rise in foam with the assumption that the bubbles are spherical with a radius formula_6. with velocity in units of centimeters per second. ρ and ρ is the density for a gas and liquid respectively in units of g/cm and ῃ and ῃ is the viscosity of the gas and liquid g/cm·s and g is the acceleration in units of cm/s. However, since the density and viscosity of a liquid is much greater than the gas, the density and viscosity of the gas can be neglected, which yields the new equation for velocity of bubbles rising"
"Relative velocity The ""relative velocity"" formula_1 (also formula_2 or formula_3) is the velocity of an object or observer B in the rest frame of another object or observer A. We begin with relative motion in the classical, (or non-relativistic, or the Newtonian approximation) that all speeds are much less than the speed of light. This limit is associated with the Galilean transformation. The figure shows a man on top of a train, at the back edge. At 1:00 pm he begins to walk forward at a walking speed of 10 km/h (kilometers per hour). The train is moving at 40"
"Spatial acceleration In physics the study of rigid body motion provides for several ways of defining the acceleration state of a rigid body. The classical definition of acceleration entails following a single particle/point along the rigid body and observing its changes of velocity. In this article the notion of spatial acceleration is explored, which entails looking at a fixed (unmoving) point in space and observing the changes of velocity of whatever particle/point happens to coincide with the observation point. This is similar to the acceleration definition fluid dynamics where typically one can measure velocity and/or accelerations on a fixed locate"
"Metre per hour Metre per hour (American spelling: meter per hour) is a metric unit of both speed (scalar) and velocity (Vector (geometry)). Its symbol is m/h or m·h (not to be confused with the imperial unit symbol mph. By definition, an object travelling at a speed of 1 m/h for an hour would move 1 metre. The term is rarely used however as the units of metres per second and kilometres per hour are considered sufficient for the majority of circumstances. Metres per hour can however be convenient for documenting extremely slow moving objects. A Garden Snail for instance,"
"change of the velocity vector. The average acceleration of a particle over a time interval is defined as the ratio. where ΔV is the difference in the velocity vector and Δ""t"" is the time interval. The acceleration of the particle is the limit of the average acceleration as the time interval approaches zero, which is the time derivative, or Thus, acceleration is the first derivative of the velocity vector and the second derivative of the position vector of that particle. Note that in a non-rotating frame of reference, the derivatives of the coordinate directions are not considered as their directions"
"unit of acceleration is formula_19 or metre per second squared. If formula_20 is the average acceleration and formula_21 is the average velocity over the time interval formula_9 then mathematically, formula_23 The instantaneous acceleration is the limit of the ratio formula_24 and formula_9 as formula_9 approaches zero i.e., formula_27 formula_28 The rate of change of acceleration, the third derivative of displacement is known as jerk. The SI unit of jerk is formula_29. In the UK jerk is also known as jolt. The rate of change of jerk, the fourth derivative of displacement is known as jounce. The SI unit of jounce"
"Acceleration (differential geometry) In mathematics and physics, acceleration is the rate of change of velocity of a curve with respect to a given linear connection. This operation provides us with a measure of the rate and direction of the ""bend"". Consider a differentiable manifold formula_1 with a given connection formula_2. Let formula_3 be a curve in formula_1 with tangent vector, i.e. velocity, formula_5, with parameter formula_6. The acceleration vector of formula_7 is defined by formula_8, where formula_9 denotes the covariant derivative associated to formula_2. It is a covariant derivative along formula_7, and it is often denoted by With respect to"
"object. The four-velocity is the rate of change of four-position with respect to the proper time along the curve. The velocity, in contrast, is the rate of change of the position in (three-dimensional) space of the object, as seen by an observer, with respect to the observer's time. The value of the magnitude of an object's four-velocity, i.e. the quantity obtained by applying the metric tensor to the four-velocity , that is , is always equal to , where is the speed of light. Whether the plus or minus sign applies depends on the choice of metric signature. For an"
"Speed In everyday use and in kinematics, the speed of an object is the magnitude of its velocity (the rate of change of its position); it is thus a scalar quantity. The average speed of an object in an interval of time is the distance travelled by the object divided by the duration of the interval; the instantaneous speed is the limit of the average speed as the duration of the time interval approaches zero. Speed has the dimensions of distance divided by time. The SI unit of speed is the metre per second, but the most common unit of"
"estimate how much work they can complete in a given time period based on how quickly similar work was previously completed. Velocity is relative measure. In other words, the raw numbers mean little; it is the trend that matters. One problem with velocity is that it conflates work done with planning accuracy. In other words, a team can inflate velocity by estimating tasks more conservatively. If a team says that a task will take four hours or is worth 4 points instead of taking two hours or being worth two points, their velocity will look better. A second problem with"