Download October 23 CP

October 23 CP
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Finding the Resultant of Two Forces by Using Vectors
Check your homework answers below:
6. sin B = .5657
Ref. Angle = 34
I: 34
II: 146
One possible triangle.
2. sin B = 1.5
No possible triangles.
4. sin A = 1/3
Ref. Angle = 19
I: 19
II: 161
One possible triangle.
8. sin B = .7648
Ref. Angle = 50
I: 50
II: 130
Two possible triangles.
Vector: drawn as a ray whose direction represents the direction of the force and whose length represents the magnitude of the force
Resultant: the combined result of two vectors acting on the same body (the resultant is another vector)
Examples...
Description of Forces
Direction of Resultant
forces in the same direction
same direction
sum of 2 forces
direction of stronger force
difference between the two forces
Magnitude of Resultant
10
1.
forces in opposite directions
forces in different directions
4
Resultant:
The vectors that represent the applied forces form 2 adjacent sides of a parallelogram, and the vector that represents the resultant force is the diagonal of this parallelogram.
2.
4
Resultant:
10
3. Two forces of 25 and 15 pounds act on a body so that the angle between them is 75 degrees. Find to the nearest pound the magnitude of the resultant.
October 23 CP
4. A resultant force of 143 pounds is needed to move a heavy box. Two applied forces act at angles of 36 degrees and 48 degrees with the resultant. Find to the nearest pound the magnitude of the larger force.
5. Two forces of 14 and 30 act on a body forming an obtuse angle with each other. If the resultant force has a magnitude of 20, find the angle between the two forces to the nearest degree.
6. Two forces act on a body at an angle of 120 degrees. The forces are 28 pounds and 35 pounds.
(a) Find the magnitude of the resultant force to the nearest tenth of a pound.
(b) Find the angle formed by the greater of the two forces and the resultant force to the nearest degree.
Homework: p. 844 ­ 845 (1 ­ 5)