Question

A particle moves in a circular orbit under the action of a central attractive force inversely proportional to the distance '$r$' .The speed of the particle is

• A. proportional to $r^3$
• B. independent of $r$
• C. proportional to $r^2$
• D. proportional to $1/r$

Answer 1

Answer: (B)

independent of $r$

Centripetal force, $F=\frac{m{v}^2}{r}$ so

$⟹k/r=\frac{m{v}^2}{r}$

$Thus,m{v}^2=k$

$So,visindependentof$r$