Answer:
ma = 48.48kg
Explanation:
To find the mass of the astronaut, you first calculate the mass of the chair by using the information about the period of oscillation of the empty chair and the spring constant. You use the following formula:
(1)
mc: mass of the chair
k: spring constant = 600N/m
T: period of oscillation of the chair = 0.9s
You solve the equation (1) for mc, and then you replace the values of the other parameters:
(2)
Next, you calculate the mass of the chair and astronaut by using the information about the period of the chair when the astronaut is sitting on the chair:
T': period of chair when the astronaut is sitting = 2.0s
M: mass of the astronaut plus mass of the chair = ?
(3)
Finally, the mass of the astronaut is the difference between M and mc (results from (2) and (3)) :

The mass of the astronaut is 48.48 kg
The inner planets are not colder or larger than the outer ones,
and they're not comprised of gas.
The inner planets are the ones that are made of rock. ( D ).
Answer:The answer is A,B and C
Explanation: it can be use to learn universe behavior,it is also use for the measurements of velocity of galaxy,and is can also be use to indicate,galaxy motion.
Doppler effect,measures the speed which star and galaxy are moving away from us or towards us. It shows the color of wavelength to be either red shift or blue shift.
A spinning top is the answer