{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

id216_fall2011_wk4_mechanics_I

# id216_fall2011_wk4_mechanics_I - Product Design Engineering...

This preview shows pages 1–11. Sign up to view the full content.

Week 4: Mechanics I - Statics Seok-Hyung Bae ([email protected]) Product Design Engineering ID216 KAIST

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Product Design Engineering ID216 KAIST Contents Beer, Johnston Jr., Eisenberg, Vector Mechanics for Engineers: Statics /Dynamics, McGraw Hill, 2007 1
Product Design Engineering ID216 KAIST What’s Mechanics Science that describes and predicts the conditions of rest or motion of bodies under the action of forces Mechanics is an applied science - it is not an abstract or pure science; mechanics is the foundation of most engineering sciences and is an indispensable prerequisite to their study. Categories of Mechanics: Rigid bodies: Statics & Dynamics Deformable bodies Fluids 2

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Product Design Engineering ID216 KAIST Vectors Vector: parameters possessing magnitude and direction which add according to the parallelogram law (e.g., displacements, velocities, accelerations) Scalar: parameters possessing magnitude but not direction (e.g., mass, volume, temperature) Equal vectors have the same magnitude and direction. Negative vector of a given vector has the same magnitude and the opposite direction. 3
Product Design Engineering ID216 KAIST Addition of Vectors Parallelogram rule for vector addition Triangle rule for vector addition Law of cosines: Law of sines: Vector addition is commutative C.f. Multiplication of a vector by a scalar C.f. Vector subtraction 4 B PQ Q P R cos 2 2 2 2 P C Q P B Q A sin sin sin B C

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Product Design Engineering ID216 KAIST Problem 1 The two forces act on a bolt at A. Determine their resultant. 5
Product Design Engineering ID216 KAIST Problem 2 A barge is pulled by two tugboats. If the resultant of the forces exerted by the tugboats is 5000 N directed along the axis of the barge, determine: (a) the tension in each of the ropes for = 45 , (b) the value of for which the tension in rope 2 is a minimum. 6

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Product Design Engineering ID216 KAIST Rectangular Components of a Vector A vector can be resolved into perpendicular components so that the resulting parallelogram is a rectangle. Perpendicular unit vectors: parallel to the x and y axes Vector components may be expressed as products of the unit vectors with the scalar magnitudes of the vector components. 7 y x F F F sin , cos ; F F F F F F y x y x j i F j i ,
Product Design Engineering ID216 KAIST Vector Addition by Summing Components 8 j i j i j i j i j i S Q P R y x y y y x x x y x y x y x R R S Q P S Q P S S Q Q P P x y y x R R R R R 1 2 2 tan

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Product Design Engineering ID216 KAIST Problem 3 Four forces act on bolt A as shown. Determine the resultant of the force on the bolt.
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}