Solution :
Acceleration due to gravity of the earth, g 
Acceleration due to gravity at 1000 km depths is :
= 8.23 m/s
Acceleration due to gravity at 2000 km depths is :
= 6.73 m/s
Acceleration due to gravity at 3000 km depths is :
= 5.18 m/s
Acceleration due to gravity at 4000 km depths is :
= 3.64 m/s
The spring is initially stretched, and the mass released from rest (v=0). The next time the speed becomes zero again is when the spring is fully compressed, and the mass is on the opposite side of the spring with respect to its equilibrium position, after a time t=0.100 s. This corresponds to half oscillation of the system. Therefore, the period of a full oscillation of the system is
Which means that the frequency is
and the angular frequency is
In a spring-mass system, the maximum velocity of the object is given by
where A is the amplitude of the oscillation. In our problem, the amplitude of the motion corresponds to the initial displacement of the object (A=0.500 m), therefore the maximum velocity is
I guess 48 , but I’m not sure
