Awire of 3ω resistance and 15 cm length is stretched to 45 cm length. calculate the new cross sectional area.

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.

Idon’t quite understand this problem

14. a body is projected with velocity vi from a.at the same time another body is projectedvertically upwards from point b withvelocity v2 lies vertically below the highestpoint. both the bodies collide thenv2÷v1is