Relative Motion in a Plane (HSC SSCE Physics): Flashcards

Velocity depends on observer's position and motion

Viewpoint from which motion is observed and measured

$\vec{s}_{1 \text{ relative to } 2} = \vec{d}_1 - \vec{d}_2$

$\vec{v}_{1 \text{ relative to } 2} = \vec{v}_1 - \vec{v}_2$

Add the negative: $\vec{v}_1 + (-\vec{v}_2)$

Use Pythagoras: $v = \sqrt{v_x^2 + v_y^2}$

$\tan \theta = \frac{v_y}{v_x}$ or vice versa

Resolve components, subtract, recombine using Pythagoras

$v_{1 \text{ relative to } 2} = v_1 - v_2$

Different velocities in different frames of reference