Motion in a Plane
Class 11 · Motion in a Plane
Dot Product (Scalar)
A·B = |A||B|cosθ — see the projection of B onto A as theta varies.
Key Notes
01
A·B = |A||B| cosθ — a scalar.
02
A·B = Aₓ Bₓ + Aᵧ Bᵧ + A_z B_z.
03
Perpendicular vectors: A·B = 0. Parallel: A·B = AB. Anti-parallel: A·B = −AB.
04
Work = F·d; Power = F·v — both are dot products.
Formulas
Dot product (geometric)
Scalar projection times magnitude.
Dot product (algebraic)
Sum of component products.
Important Points
A·A = |A|². Useful for computing |A|² without square root.
Dot Product (Scalar) notes from sciphylab (also known as SciPhy, SciPhy Lab, SciPhy Labs, Physics Lab). Class 11 physics revision for JEE Mains, JEE Advanced, NEET UG, AP Physics 1/2/C, SAT, and CUET-UG.