At the same moment, one rock is thrown upward at 4.5 m/s and another thrown downward at 6.2 m/s. what is the relative velocity of the second rock from the perspective of the first rock? assume that up is positive. a) 10.7 m/s b) -1.7 m/s c) -10.7 m/s d) 1.7 m/s

Ahair dryer is basically a duct in which a few layers of electric resistors are placed. a small fan pulls the air in and forces it through the resistors where it is heated. air enters a 1200 w hair dryer at 100 kpa and 22°c and leaves at 47°c. the cross-sectional area of the hair dryer at the exit is 60 cm2. neglecting the power consumed by the fan and the heat losses through the walls of the hair dryer, determine (a) the volume flow rate of air at the inlet and (b) the velocity of the air at the exit.

Suppose that three astronomical objects, 1, 2, and 3 are observed to lie on a line, and the distance from object 1 to object 3 is d. object 1 has four times the mass of object 3, and seven times the mass of object 2. find the distance between objects 1 and 2 for which the net force on object 2 is zero.

Which of the following is a transformer used for? alternate a voltage produce a voltage increase or decrease a voltage eliminate a voltage