The answer is 3.02 x 10^-5
Let us assume that rocket only runs in initial energy and not using its own to flying.
Also , let upward direction is +ve and downward direction is -ve .
Initial velocity , u = 58.8 m/s .
Acceleration due to gravity , 
.
Final velocity , v - = 0 m/s .
We know , by equation of motion .
Hence, this is the required solution .
I do believe all of these but core elements can be determined by spectroscopy which includes the use of electromagnetic radiation. Both the surface and core temperature can be measured using light. Surface elements can be found because the absorption lines of different elements in the spectra of the star, but I haven't heard anything about using spectral analysis for core elements.
<h3>
Answer: 22.5 m/s</h3>
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Work Shown:
acceleration = ( finalVelocity - initialVelocity )/(change in time)
1.5 = (60 - x)/(25)
1.5*25 = 60-x
37.5 = 60-x
x = 60-37.5
x = 22.5
The initial velocity is 22.5 m/s
