<h3><u>Answer</u>;</h3>
B. When actin filaments are pulled toward the center of the sarcomere, the fiber shortens.
<h3><u>Explanation;</u></h3>
- <em><u>The events of muscle fiber shortening occurs with in the sacromeres in the fibers. </u></em>
- <em><u>Contraction of striated muscle fibers takes place as the sacromeres shorten as myosin heads pull on the actin filaments.</u></em>
- <em><u>Filament movement starts at the region or zone where thin and thick filaments overlap. </u></em>
- <em><u>Myofibril contains many sacromeres along its length and thuse myofibrils and muscle cells contract as the sacromeres contract.</u></em>
C. endothermic
An endothermic process takes heat from the surroundings while an exothermic process gives out heat to the surroundings.
Answer:
B) 2.7 g of aluminium has a volume of 1 cm^3
Explanation:
Density can be defined as mass all over the volume of an object.
Simply stated, density is mass per unit volume of an object.
Mathematically, density is given by the equation;

If the density of aluminum is 2.7 g/cm³, it simply means that 2.7 g of aluminium has a volume of 1 cm³
Check:
Given the following data;
Mass = 2.7 grams
Volume = 1 cm³
Substituting into the formula, we have;

Density = 2.7 g/cm³
Answer:
1.99 parsecs.
Explanation:
We have been given that the most recently discovered system close to Earth is a pair of brown dwarfs known as Luhman 16. It has a distance of 6.5 light-years.
We know that one light year equals to 0.306601 parsecs. To convert 6.5 light-years to parsecs, we will multiply 0.306601 by 6.5.



Therefore, Luhman 16 is approximately 1.99 parsecs away from the Earth.
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