Question

Two satellites of masses m and 4m orbit the earth in circular orbits of radii 8r and r respectively. The ratio of their orbital speeds is ____________.

Options

• 1

• `1/sqrt3`

• `1/3`

• `1/(2sqrt2)`

Answer 1

Two satellites of masses m and 4m orbit the earth in circular orbits of radii 8r and r respectively. The ratio of their orbital speeds is `1/(2sqrt2)`.

Explanation:

`"Orbital speed v" prop 1/sqrt"r"`

`therefore "v"_1/"v"_2 = sqrt("r"_2/"r"_1) = sqrt("r"/(8"r")) = 1/(2sqrt2)`