Q.4) Two table tennis balls hang with their centers 10.0 cm apart. The charge on ball A is +12x10°C, and the charge on Ball B is -15x10°C. What is the force of
attraction between the balls?

Acar moves a distance of 50.0 km west, followed by a distance of 64.9 km north what was the magnitude of the displacement of the car, in units of kilometers?

Air initially at 0.75 bar, 1000 k, and occupying a volume of 0.12 m^3 undergoes two processes. process 1-2: the air is compressed isothermally until the volume is halved. process 2-3: the air undergoes a constant pressure process until the volume is halved again. assume ideal gas behavior. a) determine the mass of the air, in kg. b) the work and the heat transfer for each of the two processes, in kj. (100 kj = 1 bar . m^3)

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.