Physics
A white and smooth surface is

Good absorber and bad reflector of heat
Bad absorber and good reflector of heat
Good absorber and good reflector of heat
Bad absorber and bad reflector of heat

ANSWER DOWNLOAD EXAMIANS APP

Physics
Railway tracks are banked on curves

necessary centripetal force may be obtained from the horizontal component of the weight of the train
the train may not fly off in the opposite direction
to avoid frictional force between the tracks and wheels
necessary centrifugal force may be obtained from the horizontal component weight of the train

ANSWER DOWNLOAD EXAMIANS APP