Components the a Vector

Vectors are geometric representations of magnitude and also direction and can it is in expressed as arrows in 2 or 3 dimensions.

You are watching: Can the magnitude of a vector be negative

Key Takeaways

Key PointsVectors have the right to be damaged down into two components: magnitude and also direction.By acquisition the vector to it is in analyzed together the hypotenuse, the horizontal and vertical contents can be found by perfect a appropriate triangle. The bottom edge of the triangle is the horizontal component and the next opposite the edge is the upright component.The angle that the vector provides with the horizontal can be offered to calculation the size of the 2 components.Key Termscoordinates: number indicating a position with respect to some axis. Ex: \textx and also \texty works with indicate position relative to \textx and \texty axes.axis: An imagine line approximately which things spins or is symmetrically arranged.magnitude: A number assigned to a vector indicating its length.


Vectors space geometric depictions of magnitude and also direction i beg your pardon are frequently represented by directly arrows, starting at one suggest on a name: coordinates axis and ending in ~ a different point. All vectors have actually a length, referred to as the magnitude, which to represent some top quality of attention so that the vector might be compared to another vector. Vectors, being arrows, likewise have a direction. This differentiates them native scalars, which space mere numbers without a direction.

A vector is defined by that magnitude and also its orientation v respect to a collection of coordinates. It is often helpful in evaluating vectors to break them right into their ingredient parts. For two-dimensional vectors, these materials are horizontal and vertical. For 3 dimensional vectors, the magnitude component is the same, however the direction ingredient is to express in regards to \textx, \texty and \textz.

Decomposing a Vector

To visualize the procedure of decomposing a vector into its components, begin by illustration the vector indigenous the origin of a collection of coordinates. Next, attract a directly line native the origin along the x-axis till the line is even with the tip of the initial vector. This is the horizontal component of the vector. To find the upright component, attract a line straight up indigenous the end of the horizontal vector until you reach the reminder of the original vector. Girlfriend should find you have a best triangle such that the initial vector is the hypotenuse.

Decomposing a vector right into horizontal and also vertical materials is a very useful method in expertise physics problems. Whenever you see activity at an angle, you should think of that as relocating horizontally and also vertically in ~ the exact same time. Simple vectors in this means can speed calculations and aid to save track the the activity of objects.

Components that a Vector: The original vector, defined relative come a set of axes. The horizontal ingredient stretches indigenous the begin of the vector to its furthest x-coordinate. The upright component follow me from the x-axis come the many vertical suggest on the vector. Together, the two components and also the vector type a best triangle.


A Vector: an instance of a vector. Vectors space usually represented by arrows through their length representing the magnitude and their direction represented by the direction the arrowhead points.

Vectors need both a magnitude and a direction. The magnitude of a vector is a number for comparing one vector come another. In the geometric translate of a vector the vector is represented by one arrow. The arrowhead has two parts that define it. The two parts are its length which to represent the magnitude and its direction v respect to some set of coordinate axes. The higher the magnitude, the much longer the arrow. Physical ideas such together displacement, velocity, and acceleration are all examples of quantities that can be represented by vectors. Each of these quantities has actually both a size (how much or exactly how fast) and a direction. In order to specify a direction, there should be something to which the direction is relative. Typically this reference allude is a collection of coordinate axes choose the x-y plane.

Scalars differ from vectors in that they carry out not have a direction. Scalars space used generally to stand for physical amounts for which a direction does no make sense. Some examples of this are: mass, height, length, volume, and area. Talking about the direction of these quantities has actually no definition and so they cannot be expressed together vectors.

Key Takeaways

Key PointsTo include vectors, put the an initial one on a set of axes with its tail in ~ the origin. Location the next vector v its tail in ~ the previous vector’s head. When there are no much more vectors, attract a directly line indigenous the beginning to the head of the last vector. This heat is the amount of the vectors.To subtract vectors, proceed as if including the two vectors, however flip the vector to be subtracted throughout the axes and then join it tail to head together if adding.Adding or individually any number of vectors returns a result vector.Key Termsorigin: The facility of a coordinate axis, defined as being the coordinate 0 in every axes.Coordinate axes: A collection of perpendicular lines i beg your pardon define collaborates relative to an origin. Example: x and also y name: coordinates axes define horizontal and vertical position.

Adding and Subtracting Vectors

One the the methods in i beg your pardon representing physical amounts as vectors makes evaluation easier is the ease v which vectors may be added to one another. Because vectors room graphical visualizations, addition and subtraction of vectors have the right to be excellent graphically.

The graphical method of vector enhancement is additionally known together the head-to-tail method. To start, attract a collection of name: coordinates axes. Next, draw out the first vector v its tail (base) at the beginning of the name: coordinates axes. Because that vector enhancement it does not issue which vector girlfriend draw first since enhancement is commutative, but for individually ensure that the vector you draw an initial is the one you room subtracting from. The following step is to take the next vector and also draw that such that its tail starts at the ahead vector’s head (the arrowhead side). Proceed to ar each vector at the head that the preceding one until all the vectors you wish to include are joined together. Finally, draw a right line indigenous the origin to the head that the last vector in the chain. This new line is the vector result of adding those vectors together.

Graphical addition of Vectors: The head-to-tail technique of vector enhancement requires that you lay out the very first vector along a collection of coordinate axes. Next, place the tail of the next vector top top the head the the first one. Attract a new vector native the beginning to the head of the critical vector. This brand-new vector is the sum of the initial two.

Vector with Horizontal and Vertical Components: The vector in this image has a magnitude of 10.3 units and a direction that 29.1 degrees over the x-axis. It can be decomposed into a horizontal part and a vertical component as shown.

For example, a vector v a size of 5 in ~ a 36.9 degree angle come the horizontal axis will have actually a horizontal component of 4 units and also a vertical component that 3 units. If we were to add this to one more vector of the exact same magnitude and direction, us would get a vector twice as long at the exact same angle. This have the right to be watched by including the horizontal components of the two vectors (4+4) and the two vertical materials (3+3). These enhancements give a new vector with a horizontal ingredient of 8 (4+4) and a vertical component the 6 (3+3). To find the result vector, simply place the tail of the vertical component at the head (arrow side) of the horizontal component and also then attract a heat from the beginning to the head the the upright component. This new line is the result vector. It need to be double as long as the original, since both the its materials are double as huge as they were previously.

To subtract vectors by components, merely subtract the 2 horizontal components from each other and do the exact same for the vertical components. Then draw the resultant vector together you go in the ahead part.

Key Takeaways

Key PointsA vector is a amount with both magnitude and also direction.A scalar is a amount with only magnitude.Multiplying a vector through a scalar is indistinguishable to multiply the vector’s size by the scalar. The vector lengthens or shrinks however does not change direction.Key Termsvector: A command quantity, one v both magnitude and also direction; the between two points.magnitude: A number assigned to a vector denote its length.scalar: A quantity that has actually magnitude yet not direction; to compare vector.


Although vectors and also scalars represent different varieties of physical quantities, the is sometimes vital for them come interact. While adding a scalar to a vector is impossible due to the fact that of their various dimensions in space, that is feasible to multiply a vector through a scalar. A scalar, however, can not be multiply by a vector.

To multiply a vector by a scalar, just multiply the comparable components, the is, the vector’s magnitude by the scalar’s magnitude. This will result in a new vector with the same direction but the product that the 2 magnitudes.


For example, if you have actually a vector A v a certain magnitude and direction, multiply it by a scalar a v magnitude 0.5 will offer a new vector with a size of fifty percent the original. Similarly if you take it the number 3 i beg your pardon is a pure and also unit-less scalar and multiply it come a vector, you acquire a version of the initial vector i m sorry is 3 times together long. As a more physical instance take the gravitational pressure on an object. The pressure is a vector v its magnitude relying on the scalar known as mass and also its direction being down. If the massive of the object is doubled, the force of heaviness is doubled together well.

Multiplying vectors by scalars is really useful in physics. Many of the units provided in vector amounts are inherently scalars multiplied by the vector. Because that example, the unit of meters per 2nd used in velocity, i m sorry is a vector, is consisted of of two scalars, which room magnitudes: the scalar of size in meters and the scalar that time in seconds. In bespeak to make this conversion indigenous magnitudes to velocity, one need to multiply the unit vector in a particular direction by these scalars.

Scalar Multiplication: (i) multiply the vector \textA through the scalar \texta=0.5 yields the vector \textB which is half as long. (ii) multiply the vector \textA by 3 triples that length. (iii) doubling the massive (scalar) doubles the force (vector) the gravity.

Scalar Multiplication: (i) multiply the vector A by 0.5 halves the length. (ii) multiply the vector A by 3 triples its length. (iii) raising the massive (scalar) boosts the force (vector).

When multiply a vector by a scalar, the direction that the vector is unchanged and the size is multiplied by the magnitude of the scalar. This results in a new vector arrowhead pointing in the exact same direction as the old one yet with a much longer or much shorter length. You can also accomplish scalar multiplication with the use of a vector’s components. Once you have the vector’s components, multiply each of the components by the scalar to gain the new components and thus the brand-new vector.

A helpful concept in the study of vectors and also geometry is the principle of a unit vector. A unit vector is a vector v a length or magnitude of one. The unit vectors are various for different coordinates. In Cartesian collaborates the directions room x and y typically denoted \hat\textx and also \hat\texty. V the triangle over the letters referred to as a “hat”. The unit vectors in Cartesian works with describe a circle recognized as the “unit circle” which has radius one. This have the right to be seen by taking all the possible vectors of size one at every the possible angles in this name: coordinates system and also placing them on the coordinates. If you to be to draw a line approximately connecting every the top of every the vectors together, you would obtain a circle of radius one.

Position, Displacement, Velocity, and Acceleration as Vectors

Position, displacement, velocity, and acceleration have the right to all be presented vectors due to the fact that they are defined in regards to a magnitude and a direction.

Learning Objectives

Examine the applications of vectors in evaluating physical quantities

Key Takeaways

Key PointsVectors are arrows consisting of a magnitude and a direction. They are provided in physics to stand for physical quantities that also have both magnitude and also direction.Displacement is a physics term definition the distance of an object from a reference point. Since the displacement consists of two piece of information: the distance from the reference point and the direction far from the point, it is well stood for by a vector.Velocity is identified as the price of readjust in time of the displacement. To recognize the velocity of an item one must know both how quick the displacement is changing and in what direction. As such it is additionally well represented by a vector.Acceleration, gift the rate of readjust of velocity additionally requires both a magnitude and a direction family member to some coordinates.When drawing vectors, you frequently do not have actually enough an are to draw them to the range they space representing, so the is necessary to signify somewhere what scale they space being attracted at.Key Termsvelocity: The rate of change of displacement with respect to change in time.displacement: The length and direction of a directly line between two objects.acceleration: the rate at i beg your pardon the velocity of a body changes with time

Use the Vectors

Vectors can be used to stand for physical quantities. Most frequently in physics, vectors are used to represent displacement, velocity, and also acceleration. Vectors are a mix of magnitude and also direction, and also are drawn as arrows. The length represents the magnitude and also the direction of that quantity is the direction in which the vector is pointing. Due to the fact that vectors are constructed this way, that is advantageous to analyze physical amounts (with both size and direction) together vectors.


In physics, vectors room useful because they can visually stand for position, displacement, velocity and also acceleration. When drawing vectors, you regularly do not have enough an are to attract them come the range they room representing, so that is vital to represent somewhere what range they space being attracted at. Because that example, when drawing a vector that represents a magnitude of 100, one may attract a line that is 5 units long at a scale of \displaystyle \frac120. When the station of the scale is multiply by the drawn magnitude, it must equal the really magnitude.

Position and also Displacement

Displacement is characterized as the distance, in any kind of direction, of an item relative come the place of an additional object. Physicists usage the principle of a place vector as a graphical device to visualize displacements. A place vector expresses the position of an item from the origin of a name: coordinates system. A position vector can additionally be supplied to display the position of an item in relationship to a reference point, secondary object or initial position (if analyzing how far the object has actually moved native its initial location). The position vector is a straight line attracted from the arbitrary beginning to the object. Once drawn, the vector has a length and a direction loved one to the coordinate device used.


Velocity is additionally defined in regards to a magnitude and also direction. To say the something is gaining or losing velocity one must also say just how much and also in what direction. For example, an plane flying in ~ 200 \frac\textkm\texth to the northeast deserve to be represented by one vector pointing in the northeast direction with a magnitude of 200 \frac\textkm\texth. In drawing the vector, the magnitude is only crucial as a means to compare 2 vectors of the same units. So, if there to be another airplane flying 100 \frac\textkm\texth come the southwest, the vector arrow should be half as long and also pointing in the direction that southwest.


Acceleration, being the time rate of readjust of velocity, is created of a magnitude and a direction, and also is attracted with the same concept as a velocity vector. A worth for acceleration would certainly not be beneficial in physics if the magnitude and direction that this acceleration was unknown, i beg your pardon is why this vectors space important. In a totally free body diagram, because that example, of an object falling, it would be beneficial to use an acceleration vector near the object to denote its acceleration in the direction of the ground. If gravity is the only pressure acting on the object, this vector would be pointing downward v a size of 9.81 \frac\textm\texts^2 of 32.2 \frac\textft\texts^2.

See more: Taco Bell Weight Watcher Points For Taco Bell Weight Watchers Points Guide

Vector Diagram: right here is a man walking increase a hill. His direction of travel is defined by the edge theta relative to the vertical axis and by the size of the arrowhead going up the hill. That is also being accelerated downward through gravity.