Which of the following is not true concerning the layers of the earth? a. the core is mostly composed of metals. b. the mantle has both solid and liquid regions. c. the layers of earth are uniform in thickness. d. the lithosphere includes both the crust and upper, solid mantle. select the best answer from the choices provided a b c d

As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. there is no one around to , so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. you pull up on the rope to lift the box. use g for the magnitude of the acceleration due to gravity and neglect friction forces. once you have pulled hard enough to start the box moving upward, what is the magnitude f of the upward force you must apply to the rope to start raising the box with constant velocity? express the magnitude of the force in terms of m, the mass of the box.