A led glows when an electric current moves in one direction but not the other what type of material is the LED

Study the following reaction carefully. what classification should this reaction have? 4al + 3o2 2al2o3synthesisdecompositionsingle replacementdouble displacement

Truck traveling west on the highway experiences an acceleration to the east. what could be the cause of this acceleration

Astudent weighing 700 n climbs at constant speed to the top of an 8 m vertical rope in 10 s. the average power expended by the student to overcome gravity is most nearly