<span>D. Atoms of all elements contain protons, but the number of protons is different for every element.
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Here We can use principle of angular momentum conservation
Here as we know boy + projected mass system has no external torque
Since there is no torque so we can say the angular momentum is conserved

now we know that
m = 2 kg
v = 2.5 m/s
L = 0.35 m
I = 4.5 kg-m^2
now plug in all values in above equation

![1.75 = [4.5 + 0.245]\omega](https://tex.z-dn.net/?f=1.75%20%3D%20%5B4.5%20%2B%200.245%5D%5Comega)


so the final angular speed will be 0.37 rad/s
They believe the distortions happened when two galaxies collided.
Hope This Helps :)