A ladder with a mass of 10 kg is leaning on a smooth (i. e., negligible friction) wall. The other end is on the ground, where friction keeps it from sliding. The ladder is 4.0 m long, and its center of mass is at its center. It touches the wall 3.2 m above the ground. The magnitude of the force that the wall exerts on the ladder:

These models show the electron structures of two different nonmetal elements. which element is likely more reactive, and why? element 1 is more reactive because it has fewer electron shells and is toward the top of its group on the periodic table. element 1 is more reactive because it has more electrons in its valence shell and is farther to the right on the periodic table. element 2 is more reactive because it does not have a valence shell close to the nucleus, so it will attract electrons. element 2 is more reactive because it does not have a full valence shell, so it will attract electrons.

Astudent is given an assignment to demonstrate diffraction. he takes a photograph of a straw in a glass of water. the straw appears bent at the water level. which best describes this example? a) this is a good example of diffraction. b) this is an example of dispersion and not diffraction. c) this is an example of refraction and not diffraction. d) this is an example of reflection and not diffraction.

Gordon is going for a run through the park, but it is cold outside. the low outside temperature could affect his personal safety.