<em>D. Less luminous than those on the right []</em>
Explanation:
Given that,
Mass of the rock climber, m = 90 kg
Original length of the rock, L = 16 m
Diameter of the rope, d = 7.8 mm
Stretched length of the rope, 
(a) The change in length per unit original length is called strain. So,
(b) The force acting per unit area is called stress.
(c) The ratio of stress to the strain is called Young's modulus. So,
Hence, this is the required solution.
Physical Science is the study of non-living systems, as opposed to a study of biological sciences or living systems. It consists of physics, chemistry, astronomy and earth science. It also includes scientific method and experimentation
<h2>Answer:</h2>
<em>Metals are both good heat conductors and good electrical conductors because of the </em><em>looseness of outer electrons in metal atoms</em>
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Unlike nonmetals that are insulators, most metals are both good heat conductors and good electrical conductors. This is because within a solid metal there is one or more outer electrons in each atom that become detached and can move freely through the solid metal, but <em>what about the other electrons?</em> Well, the
y remain bound to the positively charged nuclei, and bound within the material in almost fixed positions. On the other hand, insulators are material having few, very few or no electrons that are allowed to move freely through the material.
