Which element is found in group 17 and period 2

Ingrid wrote the hypothesis below. if the temperature of a liquid increases, the density of the liquid decreases because the particles move farther apart. what are the variables in her hypothesis?

Ahorizontal force of 400.0 n is required to pull a 1760 n truck across the floor at a constant speed. find the coefficient of sliding friction.

Determine the moment of the force f about an axis extending between a and c. express the result as a cartesian vector. a is at the origin, c is at (4,3,0) and f = (4i + 12j -3k) lb coming out of b (4,3,-2).