Edward travels 150 kilometers due west and then 200 kilometers in a direction 60° north of west. what is his displacement in the westerly direction

d_{x}=v.cos\O \\ d_{x}=200. \frac{1}{2}  \\ d_{x}=100km

\Delta S= d_{o}+d_{x} \\ \Delta S= 150+100 \\ \boxed {\Delta S= 250 km}

when insulating materials rub against each other, they may become electrically charged . electrons , which are negatively charged, may be 'rubbed off' one material and on to the other. the material that gains electrons becomes negatively charged. the material that loses electrons is left with a positive charge.