AIPMT 2010 Physics and Chemistry Paper

Orbit speed of the satellite around the earth is
u=√‌

GM

r

Where,
G= Universal gravitational constant
M= Mass of earth
r= Radius of the orbit of the satellite
For satellite A
rA=4R,uA=3V‌‌uA=√‌

GM

rA

......(i)
For satellite B
rB=R,uB=?‌‌uB=√‌

GM

rB

....(ii)
Dividing equation (ii) by equation (i), we get
∴‌‌‌

UB

UA

=√‌

rA

rB

‌‌UB=UA√‌

rA

rB

Substituting the given values, we get
uB=3V√‌

4R

R

‌‌uB=6V