Percy pulls on a rope that is held up by a pulley, like the one shown. the pulley is near the ceiling, and the other end of the rope is attached to a crate. percy applies 75 n of force to the rope, and the rope lifts the crate by applying a force of 75 n.

what is the mechanical advantage of the machine?
a. 0
b. 1
c. 150
d. 5625

The law of the conservation of momentum says that the total momentum of any closed and isolated system cannot

Aperson touches a large chunk of ice with their hand and remarks, “this is making me cold.” explain what this person is feeling. is the ice transferring “cold” to the person? is there a heat transfer occurring? explain.

Atrain is traveling at 30.0 m/s relative to the ground in still air. the frequency of the note emitted by the train whistle is 262 hz. the speed of sound in air should be taken as 344 m/s. what frequency (f approach) is heard by a passenger on a train moving at a speed of 18.0 m/s relative to the ground in a direction opposite to the first train and approaching it? what frequency (f recede) is heard by a passenger on a train moving at a speed of 18.0 m/s relative to the ground in a direction opposite to the first train and receding from it?