The correct answer for the question that is being presented above is this one: "a. the wavelength of light emitted by the star." The mass of a star can be determined by studying <span>the wavelength of light emitted by the star. It also has something to do with the gravitational force that it exerts.</span>
To solve this problem we will apply the linear motion kinematic equations, which describe the change in velocity, depending on the acceleration and the distance traveled, that is,

Where,
= Final Velocity
= Initial Velocity
a = Acceleration
h = height
Our values are given as,

Replacing we have,



Therefore the height of the cliff is 121ft
2Mg + 2HCl →2MgCl + 2H₂
Balanced is:
4Mg + 4HCl → 4MgCl + 2H₂
I Hope I Helped
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