As airplane is flying at 800 km/hour. No-slip boundary condition ensures that the velocity of a fluid particle on the airplane surface is km/hour to an observer on the ground.

A10nc charge sits at a point in space where the magnitude of the electric field is 1500 n/c. what will the magnitude of the field be if the 10 nc charge is replaced by a 20 nc charge? assume the system is big enough to consider the charges as small test charges.