While exploring a castle, Exena the Exterminator is spotted by a dragon that chases her down a hallway. Exena runs into a room and attempts to swing the heavy door shut before the dragon gets her. The door is initially perpendicular to the wall, so it must be turned through 90 degrees to close. The door is 3.00 m tall and 1.25 m wide, and it weighs 750 N. You can ignore any friction. If Exena applies a force of 220 N at the edge of the door, what is the minimum time does it take her to close the door

Ithink it is letter b, i may be wrong but i think that is the answer

A.throttle body— mounted regulator

Part of the text of the exercise is missing.complete text: "a semiconductor laser in a cd player has an output wavelength of 780nm and a power level of 0.10mw. how many photons strike the cd surface during the player of a cd 69 minutes in length? ? "solutionthe power is the energy per unit of time; the laser power is  , and it is applied for a time t of  . from the previous equation we can find the total energy delivered by the laser during this time: then we can find the frequency of the photons of the laser light. in fact, we know the relatioship between c (speed of light), f (frequency) and  (wavelength): using  and  , we getfrom this, we can find the energy carried by one single photon of this frequency: and finally, we can find the number of photons dividing the total energy delivered by the laser by the energy carried by one single photon: