Vectors
- Vectors are quantities that have both magnitude and direction.
- They are often represented by an arrow where the length of the arrow represents the magnitude and the direction of the arrow represents the direction of the vector.
- Vectors can be added, subtracted, and multiplied by scalars.
- Scalar multiplication involves multiplying the magnitude of the vector by a scalar.
- Vectors can also be multiplied using the dot product and cross product.
Examples:
- Displacement of an object
- Force exerted on an object
- Velocity of an object
Equations:
- Magnitude of a vector: |πβ | = β(ππ₯Β² + ππ¦Β²)
- Unit vector: π’β = πβ / |πβ |
- Vector Addition
- Vectors can be added together using the parallelogram law.
- To add two vectors, place the tail of the second vector at the head of the first vector.
- The sum of the two vectors is the vector that extends from the tail of the first vector to the head of the second vector.
- The order in which the vectors are added does not matter; the result will be the same.
- Vector addition is both commutative and associative.
Example:
- A vector πβ = 3πΜ + 2πΜ and πβ = -πΜ + 4πΜ. Find the sum πβ = πβ + πβ.
Equation:
- πβ = πβ + πβ = (3πΜ + 2πΜ) + (-πΜ + 4πΜ)
- Vector Subtraction
- Vector subtraction is similar to vector addition, but in the opposite direction.
- To subtract two vectors, we add the negative of the second vector to the first vector.
- The result is a vector that points from the tail of the second vector to the head of the first vector.
Example:
- A vector πβ = 3πΜ + 2πΜ and πβ = -πΜ + 4πΜ. Find the difference πβ = πβ - πβ.
Equation:
- πβ = πβ - πβ = (3πΜ + 2πΜ) - (-πΜ + 4πΜ)
- Scalar Multiplication
- Scalar multiplication involves multiplying a vector by a scalar (a real number).
- To multiply a vector by a scalar, multiply each component of the vector by the scalar.
- The direction of the resulting vector remains the same, but the magnitude is scaled by the scalar.
Example:
- Multiply the vector πβ = 2πΜ + 3πΜ by the scalar 5.
Equation:
- πβ = 5(2πΜ + 3πΜ)
- Dot Product
- The dot product, also known as the scalar product, is a binary operation that takes two vectors and produces a scalar.
- The dot product of two vectors πβ and πβ is denoted as πβ Β· πβ.
- The dot product is computed by multiplying the corresponding components of the vectors and summing the products.
- The dot product is commutative: πβ Β· πβ = πβ Β· πβ.
- Geometrically, the dot product can be interpreted as the product of the magnitudes of the two vectors and the cosine of the angle between them.
Example:
- Calculate the dot product of πβ = 2πΜ + 3πΜ and πβ = -πΜ + 4πΜ.
Equation:
- πβ Β· πβ = (2πΜ + 3πΜ) Β· (-πΜ + 4πΜ)
- Properties of the Dot Product
- Distributive Property: πβ Β· (πβ + πβ) = πβ Β· πβ + πβ Β· πβ
- Scalar Multiplication: (ππβ) Β· πβ = πβ Β· (ππβ) = πππβ Β·
- Dot Product with the Zero Vector: πβ Β· π£β = 0
Example:
- Verify the distributive property: (πβ Β· πβ)β + (πβ Β· πβ)β = πβ Β· (πβ + πβ)β.
Equation:
- (πβ Β· πβ)β + (πβ Β· πβ)β = πβ Β· (πβ + πβ)β = ?
- Cross Product
- The cross product, also known as the vector product, is a binary operation that takes two vectors and produces another vector.
- The cross product of two vectors πβ and πβ is denoted as πβ Γ πβ.
- The cross product is computed using the determinant of a 3x3 matrix involving the components of the vectors.
- The resulting vector is orthogonal to both the original vectors and its direction is determined by the right-hand rule.
Example:
- Calculate the cross product of πβ = 2πΜ + 3πΜ + πΜ and πβ = -πΜ + 4πΜ - 2πΜ.
Equation:
- πβ Γ πβ = (2πΜ + 3πΜ + πΜ) Γ (-πΜ + 4πΜ - 2πΜ)
- Properties of the Cross Product
- The cross product is distributive: πβ Γ (πβ + πβ) = πβ Γ πβ + πβ Γ πβ
- Scalar Multiplication: πβ Γ (ππβ) = (πβ Γ πβ)πβ = ππβ Γ πβ
- The cross product of two parallel vectors is the zero vector: πβ Γ πβ = π£β
Example:
- Verify the distributive property: πβ Γ (πβ + πβ) = πβ Γ πβ + πβ Γ πβ.
Equation:
- πβ Γ (πβ + πβ) = πβ Γ πβ + πβ Γ πβ = ?
- Applications of Vectors: Displacement
- Vectors are commonly used to represent the displacement of an object.
- Displacement is a vector quantity that represents the change in position of an object from its initial position to its final position.
- Displacement is defined as the vector that points from the initial position to the final position of the object.
- Displacement can be measured in terms of magnitude and direction or using components in a coordinate system.
Example:
- An object moves 5 meters east and then 3 meters north. What is the displacement of the object?
Equation:
- πβ = 5πΜ + 3πΜ
- Applications of Vectors: Force
- Vectors are used to represent forces acting on an object.
- Force is a vector quantity that represents the physical interaction between two objects.
- A force is characterized by its magnitude and direction.
- Forces can be added and subtracted using vector addition and subtraction.
Example:
- Two forces, πΉβ1 = 5πΜ - 2πΜ and πΉβ2 = -3πΜ + πΜ, act on an object. What is the resulting force?
Equation:
- πΉβ = πΉβ1 + πΉβ2
- Applications of Vectors: Velocity
- Vectors are commonly used to represent the velocity of an object.
- Velocity is a vector quantity that represents the rate of change of displacement with respect to time.
- Velocity is defined as the vector that points in the direction of motion and has a magnitude equal to the speed of the object.
- Velocity can be measured in terms of magnitude and direction or using components in a coordinate system.
Example:
- An object moves 10 meters east in 2 seconds. What is the velocity of the object?
Equation:
- π£β = πβ / π‘
VTP Identity
- The VTP Identity is a mathematical identity involving vectors and their cross product.
- It states that the cross product of the cross product of two vectors is equal to the vector multiplied by the dot product of the two vectors minus the dot product of the vector with the first vector.
VTP Identity Equation:
- πβ Γ (πβ Γ πβ) = (πβ Β· πβ)πβ - (πβ Β· πβ)πβ
Example:
- Given πβ = 2πΜ + 3πΜ + πΜ, πβ = -πΜ + 4πΜ - 2πΜ, and πβ = πΜ + πΜ.
- Calculate the cross product of πβ and (πβ Γ πβ) using the VTP Identity.
Equation:
- πβ Γ (πβ Γ πβ) = (πβ Β· πβ)πβ - (πβ Β· πβ)πβ = ?
Vector Projection
- The vector projection is a method used to find the component of a vector in the direction of another vector.
- It allows us to break down a vector into two components: the parallel component and the perpendicular component.
- The parallel component represents the part of the vector that lies in the same direction as the other vector.
- The perpendicular component represents the part of the vector that is perpendicular to the other vector.
Example:
- Given πβ = 5πΜ + 3πΜ and πβ = 2πΜ - πΜ.
- Find the vector projection of πβ onto πβ.
Equation:
- πβπβπβπβπβπβπβπ‘βπβπβπβ = ((πβ Β· πβ) / |πβ |Β²)πβ = ?
Angle Between Vectors
- The angle between two vectors can be calculated using the dot product.
- The dot product of two vectors can be written as the product of their magnitudes and the cosine of the angle between them.
- Using this equation, we can solve for the angle between the vectors.
Angle Equation:
- cos(ΞΈ) = πβ Β· πβ / (|πβ |β
|πβ |)
Example:
- Given πβ = 2πΜ + 3πΜ and πβ = -πΜ + 4πΜ.
- Find the angle between πβ and πβ.
Equation:
- cos(ΞΈ) = πβ Β· πβ / (|πβ |β
|πβ |) = ?
Scalar Triple Product
- The scalar triple product is a mathematical operation involving three vectors.
- It is calculated by taking the dot product of one vector with the cross product of the other two vectors.
- The scalar triple product can be used to determine whether three vectors are coplanar or not.
- If the scalar triple product is equal to zero, the three vectors are coplanar; otherwise, they are not coplanar.
Scalar Triple Product Equation:
- (πβ Γ πβ) Β· πβ
Example:
- Given πβ = 2πΜ + 3πΜ + πΜ, πβ = -πΜ + 4πΜ - 2πΜ, and πβ = πΜ + πΜ.
- Calculate the scalar triple product: (πβ Γ πβ) Β· πβ.
Equation:
- (πβ Γ πβ) Β· πβ = ?
Applications of Vectors: Work
- Vectors are used to represent work, which is the product of the force applied on an object and the displacement of the object.
- Work is a scalar quantity, but it can be represented using vectors.
- The work done on an object is given by the dot product of the force vector and the displacement vector.
- Positive work is done when the force and displacement are in the same direction, while negative work is done when they are in opposite directions.
Work Equation:
- π = πΉβ Β· πβ
- Where π is the work, πΉβ is the force vector, and πβ is the displacement vector.
Example:
- A force of 10 N is applied on an object that moves a distance of 5 meters in the same direction as the force.
- Find the work done on the object.
Equation:
- π = πΉβ Β· πβ = ?
Applications of Vectors: Torque
- Vectors are used to represent torque, which is the rotational equivalent of force.
- Torque is the product of the force applied perpendicular to the axis of rotation and the distance from the axis of rotation.
- Torque is a vector quantity that has both magnitude and direction.
- The direction of the torque vector is given by the right-hand rule, where the thumb points in the direction of the torque vector when the fingers curl in the direction of rotational motion.
Torque Equation:
- π = πΉβ Γ πβ
- Where π is the torque, πΉβ is the force vector, and πβ is the position vector or distance from the axis of rotation.
Example:
- A force of 10 N is applied perpendicular to a lever arm with a length of 2 meters.
- Find the torque generated by the force.
Equation:
- π = πΉβ Γ πβ = ?
Parametric Equations
- Parametric equations are a way of representing curves using equations that describe the coordinates of points in terms of parameters.
- The parameters are typically denoted as π‘ or π and represent the position of the point along the curve.
- Parametric equations are used to represent functions that are not easily expressed in terms of a single variable.
- They are often used to represent curves in 2D or 3D space.
Example:
- The parametric equations for a circle of radius π centered at the origin are π₯ = πcos(π‘) and π¦ = πsin(π‘), where π‘ is the parameter.
- Plot the circle using these parametric equations.
Equation:
- π₯ = πcos(π‘)
- π¦ = πsin(π‘)
Applications of Vectors: Motion in a Plane
- Vectors are used to represent motion in a plane, where objects move in both the x and y directions.
- Velocity and acceleration can