A particle is in uniform circular motion about the origin of an xy coordinate system, moving counter-clockwise with a period of 6.50 s. At one instant, its position vector (from the origin) is r with arrow = (6.00 m)i hat − (6.00 m)j. At that instant, what is its velocity in unit-vector notation?

Respuesta :

Answer:[tex]\hat{v}=\frac{1}{\sqrt{2}}\hat{i}-\frac{1}{\sqrt{2}}\hat{j}[/tex]

Explanation:

Given

Time Period [tex]T=6.5 s[/tex]

Position Vector [tex]\vec{r}=6\hat{i}-6\hat{j}[/tex]

Since it is moving in a circular path therefore magnitude of position vector will give the radius of circular path

[tex]|r|=\sqrt{6^2+6^2}[/tex]

[tex]|r|=6\sqrt{2}[/tex]

[tex]distance=velocity\times time[/tex]

[tex]6\sqrt{2}=velocity\times 6.5[/tex]

[tex]velocity=\frac{6\sqrt{2}}{6.5}[/tex]

[tex]v=1.305[/tex]

this velocity is at angle of [tex]\tan \theta =\frac{-6}{6}[/tex]

[tex]\theta =-45^{\circ}[/tex]

velocity [tex]\vec{v}=v\cos \theta +v\sin \theta [/tex]

[tex]\vec{v}=1.305\cos (-45)+1.305\sin (-45)[/tex]

Therefore unit velocity vector

[tex]\hat{v}=\frac{1}{\sqrt{2}}\hat{i}-\frac{1}{\sqrt{2}}\hat{j}[/tex]