The impact of a truck colliding at 16 km/h with a concrete pillar caused the
bumper to indent only 7.4 cm. the truck stopped. determine the acceleration of the
truck during the collision.

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.

probably not the "magnets"in the magnet, so to speak, are thought to be electrons orbiting in shells. vurrent loops two sides to the loop