What two objects have stored energy? a. ball rolling on the ground b. a small rock sitting on top of a big rock c. a stretched rubber band d. a stone lying on the ground

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.