If two uncharged objects are rubbed together and one of them acquires a negative charge, then the other one
a. remains uncharged
b. acquires a positive charge equal to twice the negative charge
c. also acquires a negative charge
d. acquires a positive charge acquires a positive charge equal to half the negative charge

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?

Aknife blade is a(n) a. lever b. screw c. wedge d. inclined plane

Electric field of the earth. the earth has a net electric charge that causes a field at points near its surface equal to 150 n> c and directed in toward the center of the earth. (a) what magnitude and sign of charge would a 60-kg human have to acquire to overcome his or her weight by the force exerted by the earth’s electric field? (b) what would be the force of repulsion between two people each with the charge calculated in part (a) and separated by a distance of 100 m? is use of the earth’s electric field a feasible means of flight? why or why not?