Not totally sure but i would say a normal? its not refraction or incidence if its perpendicular and i dont think its a mirror if its an imaginary line so yeah normal (normals are always perpendicular to their surface too i think so)
Answer:
Stress = 4.67 * 10^-7 N/m²
Explanation:
Young's modulus of the material = Stress/Strain
Given
Young's modulus = 228 x 10^9 Pa
Stress = 106,483 Pa
Required
Strain
From the formula;
Strain = Stress/Young modulus
Strain = 106,483 /228 x 10^9
Stress = 4.67 * 10^-7 N/m²
I think the correct answer from the choices listed above is option D. Galaxies exist in the universe as they form clusters that are light-years away from other clusters. Other choices are really far away from the truth. Hope this answers the question. Have a nice day.
B. opposite charge and smaller mass