Cross Product Torque (with a Cross Product Review)

Torque as the cross product, τ = r × F, is introduced. Since it's likely been a while since students last used it, the 3×3 determinant/matrix method for computing a cross product is reviewed first with a general vector example, then applied to four numeric torque examples — each one cross-checked against the magnitude equation, |r × F| = rF sinθ, combined with the right-hand rule to confirm the direction. A fifth, "Example 1b," revisits that opening general example recast as position and force vectors, to contrast how much simpler the cross-product approach is compared to using the magnitude equation and right-hand rule for a genuinely three-dimensional torque problem. Want Lecture Notes? http://www.flippingphysics.com/torque... Content Times: 0:00 Torque Review 0:55 Cross Product Torque Introduction 1:44 Example #1 5:18 Example #2 10:15 Example #3 12:04 Example #4 13:43 Example 1b Next Video: Angular Momentum Cross Product http://www.flippingphysics.com/angula... Previous Video: Angular Dart with Thin Rod Collision - Conservation of Angular Momentum Demonstration and Problem https://www.flippingphysics.com/angul... Thank you to Mr. Lane and the rest of my wonderful Patreon supporters. Please consider supporting me monthly at   / flippingphysics   Thank you to Barak Yedidia and Julie Langenbruner for being my Quality Control Team for this video. http://flippingphysics.com/quality-co... #CrossProduct #Torque #APPhysicsC Curriculum Standards: AP Physics C: Mechanics, Unit 5 Torque and Rotational Dynamics, Topic 5.3 Torque 5.3.B.2: "The torque exerted on a rigid system about a chosen pivot point by a given force is described by τ = r × F." 5.3.B.2.i: "The cross-product between two vectors, A and B, results in a vector quantity of magnitude |A × B| = AB sin θ." 5.3.B.2.ii: "The direction of the vector resulting from the cross-product of vectors A and B is perpendicular to both vectors A and B and therefore is normal to the plane defined by vectors A and B." 5.3.B.2.iii: "The direction of the vector resulting from the cross-product of vectors A and B can be qualitatively determined by applying the appropriate right-hand rule."