Slide 1: Vectors - Problems - Finding vector from STP condition
- Objective: To learn how to find a vector using the STP condition
- STP Condition: A vector that passes through a given point and is parallel to two given vectors
- Formula: Given position vectors of two points P and Q, the position vector of any point R on PQ is given by
PR = a(PQ) + b(PA)
, where a and b are scalars
"
Slide 2: Example 1
- Given:
- Point P(3, 2, -4)
- Point Q(5, 1, 6)
- Position vector of point A(1, 0, -1)
- Find the position vector of point R on PQ if PR = 3(PQ) + 2(PA).
- Solution:
- Position vector of PQ: PQ = Q - P = (5, 1, 6) - (3, 2, -4) = (2, -1, 10)
- Position vector of PR: PR = 3(PQ) + 2(PA) = 3(2, -1, 10) + 2(1, 0, -1)
- PR = (6, -3, 30) + (2, 0, -2) = (8, -3, 28)
- Therefore, the position vector of point R is (8, -3, 28).
"
Slide 3: Example 2
- Given:
- Point P(2, -3, 1)
- Point Q(4, 5, -2)
- Position vector of point A(1, 0, 3)
- Find the position vector of point R on PQ if PR = a(PQ) + b(PA).
- Solution:
- Position vector of PQ: PQ = Q - P = (4, 5, -2) - (2, -3, 1) = (2, 8, -3)
- Position vector of PR: PR = a(PQ) + b(PA) = a(2, 8, -3) + b(1, 0, 3)
- PR = (2a + b, 8a, -3a + 3b)
- The position vector of point R depends on the values of a and b.
"
Slide 4: Finding Vector using STP Condition
- Given:
- Point P(x₁, y₁, z₁)
- Point Q(x₂, y₂, z₂)
- Position vector of point A(a₁, b₁, c₁)
- To find the position vector of point R on PQ, we use the STP condition:
- To find the position vector of point R, we need to find the values of a and b.
- Let’s consider an example to understand this concept better.
"
Slide 5: Example 3
- Given:
- Point P(1, 2, -3)
- Point Q(3, -1, 4)
- Position vector of point A(0, -2, 5)
- Find the position vector of point R on PQ if PR = 2(PQ) + b(PA).
- Solution:
- Position vector of PQ: PQ = Q - P = (3, -1, 4) - (1, 2, -3) = (2, -3, 7)
- Position vector of PR: PR = 2(PQ) + b(PA) = 2(2, -3, 7) + b(0, -2, 5)
- PR = (4, -6, 14) + (0, -2b, 5b) = (4, -2b - 6, 14 + 5b)
- Therefore, the position vector of point R is (4, -2b - 6, 14 + 5b).
"
Slide 6: Properties of Vector Addition
- The position vector of any point on the line joining two points P and Q can be expressed in the form:
- PR = a(PQ) + b(PA), where a and b are scalars
- Here are some important properties of vector addition:
- If a vector is added to itself, the resulting vector is twice the original vector.
- If a vector is multiplied by a scalar ‘k’, the resulting vector is parallel to the original vector with a magnitude ‘k’ times the magnitude of the original vector.
- Let’s see an example to understand these properties.
"
Slide 7: Example 4
- Given:
- Find:
- Solution:
- Vector 2A: Scalar multiplication
- 2A = 2(2, 3, -4) = (4, 6, -8)
- Vector A + A: Vector addition
- A + A = (2, 3, -4) + (2, 3, -4) = (4, 6, -8)
- Therefore, 2A = (4, 6, -8) and A + A = (4, 6, -8).
"
Slide 8: Example 5
- Given:
- Point P(1, 2, -3)
- Point Q(3, -1, 4)
- Position vector of point A(0, -2, 5)
- Find the position vector of point R on PQ if PR = 3(PQ) - 2(PA).
- Solution:
- Position vector of PQ: PQ = Q - P = (3, -1, 4) - (1, 2, -3) = (2, -3, 7)
- Position vector of PR: PR = 3(PQ) - 2(PA) = 3(2, -3, 7) - 2(0, -2, 5)
- PR = (6, -9, 21) - (0, 4, -10) = (6, -13, 31)
- Therefore, the position vector of point R is (6, -13, 31).
"
Slide 11: Vectors - Problems - Finding vector from STP condition
- Objective: To learn how to find a vector using the STP condition
- STP Condition: A vector that passes through a given point and is parallel to two given vectors
-
Formula: Given position vectors of two points P and Q, the position vector of any point R on PQ is given by PR = a(PQ) + b(PA) , where a and b are scalars |
Slide 12: Example 1
- Given:
- Point P(3, 2, -4)
- Point Q(5, 1, 6)
- Position vector of point A(1, 0, -1)
- Find the position vector of point R on PQ if PR = 3(PQ) + 2(PA).
- Solution:
- Position vector of PQ: PQ = Q - P = (5, 1, 6) - (3, 2, -4) = (2, -1, 10)
- Position vector of PR: PR = 3(PQ) + 2(PA) = 3(2, -1, 10) + 2(1, 0, -1)
- PR = (6, -3, 30) + (2, 0, -2) = (8, -3, 28)
-
Therefore, the position vector of point R is (8, -3, 28). |
Slide 13: Example 2
- Given:
- Point P(2, -3, 1)
- Point Q(4, 5, -2)
- Position vector of point A(1, 0, 3)
- Find the position vector of point R on PQ if PR = a(PQ) + b(PA).
- Solution:
- Position vector of PQ: PQ = Q - P = (4, 5, -2) - (2, -3, 1) = (2, 8, -3)
- Position vector of PR: PR = a(PQ) + b(PA) = a(2, 8, -3) + b(1, 0, 3)
- PR = (2a + b, 8a, -3a + 3b)
-
The position vector of point R depends on the values of a and b. |
Slide 14: Finding Vector using STP Condition
- Given:
- Point P(x₁, y₁, z₁)
- Point Q(x₂, y₂, z₂)
- Position vector of point A(a₁, b₁, c₁)
- To find the position vector of point R on PQ, we use the STP condition:
- To find the position vector of point R, we need to find the values of a and b.
-
Let’s consider an example to understand this concept better. |
Slide 15: Example 3
- Given:
- Point P(1, 2, -3)
- Point Q(3, -1, 4)
- Position vector of point A(0, -2, 5)
- Find the position vector of point R on PQ if PR = 2(PQ) + b(PA).
- Solution:
- Position vector of PQ: PQ = Q - P = (3, -1, 4) - (1, 2, -3) = (2, -3, 7)
- Position vector of PR: PR = 2(PQ) + b(PA) = 2(2, -3, 7) + b(0, -2, 5)
- PR = (4, -6, 14) + (0, -2b, 5b) = (4, -2b - 6, 14 + 5b)
-
Therefore, the position vector of point R is (4, -2b - 6, 14 + 5b). |
Slide 16: Properties of Vector Addition
- The position vector of any point on the line joining two points P and Q can be expressed in the form:
- PR = a(PQ) + b(PA), where a and b are scalars
- Here are some important properties of vector addition:
- If a vector is added to itself, the resulting vector is twice the original vector.
- If a vector is multiplied by a scalar ‘k’, the resulting vector is parallel to the original vector with a magnitude ‘k’ times the magnitude of the original vector.
-
Let’s see an example to understand these properties. |
Slide 17: Example 4
- Given:
- Find:
- Solution:
- Vector 2A: Scalar multiplication
- 2A = 2(2, 3, -4) = (4, 6, -8)
- Vector A + A: Vector addition
- A + A = (2, 3, -4) + (2, 3, -4) = (4, 6, -8)
-
Therefore, 2A = (4, 6, -8) and A + A = (4, 6, -8). |
Slide 18: Example 5
- Given:
- Point P(1, 2, -3)
- Point Q(3, -1, 4)
- Position vector of point A(0, -2, 5)
- Find the position vector of point R on PQ if PR = 3(PQ) - 2(PA).
- Solution:
- Position vector of PQ: PQ = Q - P = (3, -1, 4) - (1, 2, -3) = (2, -3, 7)
- Position vector of PR: PR = 3(PQ) - 2(PA) = 3(2, -3, 7) - 2(0, -2, 5)
- PR = (6, -9, 21) - (0, 4, -10) = (6, -13, 31)
-
Therefore, the position vector of point R is (6, -13, 31). |
- Example 6:
- Given:
- Point P(1, 2, 3)
- Point Q(4, -2, 5)
- Position vector of point A(-1, 0, 1)
- Find the position vector of point R on PQ if PR = a(PQ) + b(PA).
- Solution:
- Position vector of PQ: PQ = Q - P = (4, -2, 5) - (1, 2, 3) = (3, -4, 2)
- Position vector of PR: PR = a(PQ) + b(PA) = a(3, -4, 2) + b(-1, 0, 1)
- PR = (3a - b, -4a, 2a + b)
- The position vector of point R depends on the values of a and b.
- Example 7:
- Given:
- Point P(-2, 5, 1)
- Point Q(3, -1, 4)
- Position vector of point A(0, -3, 2)
- Find the position vector of point R on PQ if PR = 2(PQ) - 3(PA).
- Solution:
- Position vector of PQ: PQ = Q - P = (3, -1, 4) - (-2, 5, 1) = (5, -6, 3)
- Position vector of PR: PR = 2(PQ) - 3(PA) = 2(5, -6, 3) - 3(0, -3, 2)
- PR = (10, -12, 6) - (0, -9, 6) = (10, -3, 0)
- Therefore, the position vector of point R is (10, -3, 0).
- Use of Vectors in Real-Life Applications:
- Navigation and GPS systems use vectors to calculate distances and directions.
- Physics, especially in mechanics and electromagnetism, utilizes vectors to describe quantities like velocity, force, or electric field.
- Computer graphics and animation use vectors to define the position, orientation, and movement of objects.
- Engineering and architecture use vectors to analyze and design structures, calculate forces, and simulate fluid flow.
- Vectors are extensively used in robotics, including robot motion planning and control algorithms.
- Properties of Vector Multiplication:
- Dot Product: The dot product of two vectors A and B, denoted as A · B, is a scalar quantity given by the formula A · B = |A| |B| cosθ, where |A| and |B| are the magnitudes of vectors A and B, and θ is the angle between them.
- Cross Product: The cross product of two vectors A and B, denoted as A × B, is a vector quantity perpendicular to both A and B, and its magnitude is given by |A × B| = |A| |B| sinθ, where θ is the angle between them. The direction of A × B can be determined using the right-hand rule.
- Example 8:
- Given:
- Vector A = (2, -1, 3)
- Vector B = (4, 0, -2)
- Find:
- Solution:
- Dot Product:
- A · B = (2)(4) + (-1)(0) + (3)(-2) = 8 - 6 = 2
- Cross Product:
- A × B = [(2)(-2) - (-1)(0), (-1)(4) - (2)(-2), (2)(0) - (-1)(4)]
- A × B = (-4, -6, 4)
- Therefore, A · B = 2 and A × B = (-4, -6, 4).
- Example 9:
- Given:
- Vector A = (1, -3, 2)
- Vector B = (-2, 4, -1)
- Find:
- Solution:
- Dot Product:
- A · B = (1)(-2) + (-3)(4) + (2)(-1) = -2 - 12 - 2 = -16
- Cross Product:
- A × B = [(1)(-1) - (-3)(4), (-3)(-2) - (1)(-1), (1)(4) - (-3)(-2)]
- A × B = (-13, 5, -10)
- Therefore, A · B = -16 and A × B = (-13, 5, -10).
- Applications of Vectors in Physics:
- Motion: Vectors are used to describe the displacement, velocity, and acceleration of objects in various types of motion, such as linear, projectile, and circular motion.
- Forces: Vectors are used to represent forces acting on objects and to calculate their resultant force and direction.
- Electric and Magnetic Fields: Vectors are used to describe