Presentation on theme: "Adding Vectors by Components. Dimension The number of coordinates needed to specify a point (Ex) 0."— Presentation transcript:
Adding Vectors by Components
Dimension The number of coordinates needed to specify a point (Ex) 0
One dimension = position on a line Two dimensions = position on a plane Three dimensions = position in 3D-space Four dimensions = 3D + time
To describe a direction
x degrees north of east = Start at east and rotate x degrees toward north. x degrees east of north = Start at north and rotate x degrees toward east.
Revisit Vectors 1) Vectors in one dimension F net = ? F 1 = 120 NF 2 = 80 N
2) Vectors in two dimensions F net = ?
Component Vectors Visualizing Vectors in 2 Dimensions | Mechanics | Khan AcademyVisualizing Vectors in 2 Dimensions | Mechanics | Khan Academy Vector resolution –Breaking a vector into the x- and y- components R x = R y = –vector R = R x = the x component of a vector, R R y = the y component of a vector, R
Example Find the x- and y-component of R if R = 15 cm and ө = 50˚.
Adding Vectors by Components Add the vectors. 15 m/s 13 m/s 40˚ 20˚
15 m/s 13 m/s 40˚ 20˚ y-axis x-axis resultant vector
40˚ 20˚ y-axis x-axis
40˚ 20˚ y-axis x-axis
15 m/s 13 m/s 40˚ 20˚ y-axis x-axis 15sin 40˚ 15cos40˚ 13sin 20˚ 13cos20˚
Example The table below represents a set of force vectors. These vectors begin at the origin of a coordinate system, and end at the coordinates given in the table. a.What is the magnitude of the resultant of the sum of these three vectors? b.What is the size of the angle, ө, that the resultant makes with the horizontal (x-axis)? Vector #x-value (N)y-value (N) A B C -10.0
Find the resultant vector. A (5, 7) B(-8, -3) C(9, -10)
8.5 R (6, -6) Answer
Find the resultant vector. A B C 3 N 4N 5N 55° 50° 40°
Example A GPS receiver indicates that your home is 15.0 km and 40.0˚ north of west, but the only path through the woods leads directly north. If you follow the path 5.0 km before it opens into a field, how far, and in what direction, would you have to walk to reach your home? *north of west = north from west
R, 15 km 40˚ 5 km, A x km, B ө ˚ A x + B x = R x 0 + B x = B x = A y + B y = R y 5 + B y = 9.6 B y = 4.6 A x = 0 B x R x = 15 cos 140˚ = A y = 5 B y R y = 15 sin 140˚ = 9.6
x km, B ө ˚ A x + B x = R x 0 + B x = B x = A y + B y = R y 5 + B y = 9.6 B y = km 4.6 km x = ө + 90˚ = cos -1 (-11.5/12.4) =158 ˚ ө = 158 ˚ - 90˚ = 68˚ vectorsx component (km)y component (km) A05 BBxBx ByBy R15 cos 140˚ = sin 140˚ = 9.6
Example A football player runs directly down the field for 35 m before turning an additonal 15 m before getting tackled. What is the magnitude and direction of the runner’s total displacement?