Suppose you increase your walking speed from 7 m/s to 11 m/s in a period of 3 s. what is your acceleration?

if i remember correctly, to get acceleration, you subtract the initial velocity from the final velocity and divide it by the time.

if you do that (11-7) / 3, it gives you 4/3 m/s^2

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.