The top of a cliff is located a distance (h) above the ground. at a distance of h/2 a bird nest sits on a branch that juts out from the wall of the cliff. one (bad) child throws a rock up from the ground as a second (bad) child throws a rock down from the top of the cliff. which rock hits the nest first if they are thrown at the same velocity, at the same time? (ignore air resistance)

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.

How do we measure or think of speed in the united states?

Which of the following changes will increase the capacitance of a parallel-plate capacitor? (there could be more than one correct choice.) a) increase the charge on the plates b) decrease the poten5al between the plates c) increase the potential between the plates d) introduce a dielectric material between the plates e) decrease the separation between the plates