In a pulley setup that has a moving pulley, a.) you have to pull the string a greater distance, but the force needed to lift the mass is cut in half b.)you have to pull the string a greater distance, and it takes more work to lift the mass c.) you don't have to pull very much to lift the mass d.)your work doubles because the pulley moves

Which explanation describes the forces involved for a person to walk down the sidewalk? a. the person's feet push backward on the sidewalk; the sidewalk pushes backward on the person. b. the person's feet push forward on the sidewalk; the sidewalk does not push on the person. c. the person's feet push backward on the sidewalk; the sidewalk pushes forward on the person. d. the person's feet push forward on the sidewalk; the sidewalk pushes forward on the person.

If the chemical properties of a substance remain unchanged and appearance or shape of a substance changes it is called a ?

Examples of states of consciousness include a. daydreaming b. dreaming during sleep c. hypnosis d. all of the above