Question

A satellite is moving around the earth with speed v in a circular orbit of radius r. If the orbit radius is decreased by 1%, its speed will

• A. Increase by 1%
• B. Increase by 0.5%
• C. Decrease by 1%
• D. Decrease by 0.5%

Answer 1

Answer: (B)

Increase by 0.5%

Answer 2

Orbital velocity $v = \sqrt { \frac { G m } { r } }$ ∴ $v \propto \frac { 1 } { \sqrt { r } }$

[If r decreases then v increases]

Percentage change in

$\therefore$orbital velocity increases by 0.5%.