In a spectrograph, black lines can be seen going through the array of colors. The pattern of these lines indicate the composition of the star.
Different elements block different parts of the spectrum, resulting in black lines.
The equation of kinetic energy is

, where v = velocity and m= mass.
So,
144.1 kg * 11.56 m/s * 1/2 = 832.898
Answer:
14 m/s
Explanation:
Using the principle of conservation of energy, the potential energy is converted to kinetic energy, assuming any losses.
Kinetic energy is given by ½mv²
Potential energy is given by mgh
Where m is the mass, v is the velocity, g is acceleration due to gravity and h is the height.
Equating kinetic energy to be equal to potential energy then
½mv²=mgh
V
Making v the subject of the formula
v=√(2gh)
Substituting 9.81 m/s² for g and 10 m for h then
v=√(2*9.81*10)=14.0071410359145 m/s
Rounding off, v is approximately 14 m/s
Equilibrium is when the opposing forces or influences are balanced. So it would be E!