Aspacecraft with a proper length of 250 m passes by an observer on the earth. according to this observer, it takes 0.770 µs for the spacecraft to pass a fixed point. determine the speed of the spacecraft as measured by the earth-based observer.

How much work is done lifting a 9.10 kg box straight up onto a shelf that is 1.80 m high?

If the chemical properties of a substance remain unchanged and appearance or shape of a substance changes it is called a ?

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.