An engine expels 350 J of heat to a cooling system at 175 K and produces 780 J of work. What must the heat input of this engine be in order to produce those results?

Light traveling in a medium with a refractive index 1.19 is incident on a plate of another medium with index of refraction 1.79. at what angle of incidence is the reflected light fully polarized?

Clothes dryer uses about 7 amps of current from a 240 volt line. how much power does it use?

Asmall object with mass 0.200 kg swings back and forth on the lower end of a light rope that is 3.00 m long. the upper end of the rope is attached to the ceiling. as the object swings through its lowest position, where the rope is vertical, the speed of the object is 5.80 m/s. at this point in the motion, what is the tension in the rope? (use g = 9.80 m/s2.)