How are work and power related to each other?

Amachinist needs to remove a tight fitting pin of material a from a hole in a block made of material b. the machinist heats both the pin and the block to the same high temperature and removes the pin easily. what statement relates the coefficient of thermal expansion of material a to that of material b? a) the situation is not possible, heating block b will shrink the hole in the material as the material expands with increasing temperatureb) material b has the same coefficient of expansion as does material ac) material b has a negative coefficient of expansion and a has a positive coefficient of expansiond) material a has a greater coefficient of expansion than does material be) material b has a greate

Which of the following harmful chemicals are found in tobacco smoke? a. carbon monoxide b. carbon dioxide c. nicotine b. carbon dioxide d. both a and c

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.