The astronaut's weight is not 60 kg anywhere, because kg is a unit of mass, not weight.
If the astronaut's mass is 60 kg, then his weight is (60 kg)x(acceleration of gravity).
That's 588 Newtons on Earth, and 58.8 Newtons on a planet with 1/10 Earth's gravity.
The astronaut's mass of 60 kg goes with her, and doesn't depend on where she is.
2. When an unbalanced force acts upon it
Think of a glass of milk resting on a table. The glass weighs a certain amount more due to the load it carries. It would be unaffected until and unbalanced force (such as a hand) carelessly knocks it over spilling the contents.
Hope this helps :)
-- The unit of frequency is "per second" (Hz), which is [reciprocal time].
-- The unit of period is "second", which is [time].
Do you see where this is going ?
'Frequency' and 'period' are reciprocals of each other.
For any wave ...
Period = (1) / (frequency) .
Frequency = (1) / (period) .
Oxygen is a gas a room temperature.