Answer:
Unbalanced forces change the motion of an object. If an object is at rest and an unbalanced force pushes or pulls the object, it will move. Unbalanced forces can also change the speed or direction of an object that is already in motion.
The greatest variation in size, mass, and luminosity occurs in elliptical galaxies.
<h3>What is Variation?</h3>
This is defined as the difference from the norm which is exhibited by objects.
In the solar system, variation in features such as size, mass, and luminosity occurs mostly in elliptical galaxies due to presence of array of stars thereby making it the most appropriate choice.
Read more about Elliptical galaxies here brainly.com/question/24985948
The speed of the pin after the elastic collision is 9 m/s east.
<h3>
Final speed of the pin</h3>
The final speed of the pin is calculated by applying the principle of conservation of linear momentum as follows;
m1u1 + mu2 = m1v1 + m2v2
where;
- m is the mass of the objects
- u is the initial speed of the objects
- v is the final speed of the objects
4(1.4) + 0.4(0) = 4(0.5) + 0.4v2
5.6 = 2 + 0.4v2
5.6 - 2 = 0.4v2
3.6 = 0.4v2
v2 = 3.6/0.4
v2 = 9 m/s
Thus, The speed of the pin after the elastic collision is 9 m/s east.
Learn more about linear momentum here: brainly.com/question/7538238
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Answer:
letter B
none zero digit are significant figures
