In the diagram below, the uniform metre rule is pivoted at X and held up at the point Y by a rope.
rope

Given that the weight of the metre rule is 4.0 N, calculate the tension in the rope that
is needed to ensure that the ruler stays horizontal.

Bone-strengthening physical activity done increases bone-mineral content and bone density in youth.

Let v1, v2, w be three linearly independent vectors in r 3 . that is, they do not all lie on the same plane. for each of the following (infinite) set of vectors, carefully sketch it in r 3 , and determine whether or not it is a vector space (i.e., a subspace of r 3 ). explain your reasoning

What are similarities and differences between refraction, reflection, diffraction and absorption?