The earth has about 80 times the mass of the earth's moon. the gravitational force exerted on the moon by the earth has what relation to the gravitational force exerted on the earth by the moon?
a.)1/80 x.
b.)the same as.
c.)zero; the earth exerts a force on the moon, but the moon is too small and too far. d.)away to exert a force on the earth.
e.)80 x.

Atrain is traveling at 30.0 m/s relative to the ground in still air. the frequency of the note emitted by the train whistle is 262 hz. the speed of sound in air should be taken as 344 m/s. what frequency (f approach) is heard by a passenger on a train moving at a speed of 18.0 m/s relative to the ground in a direction opposite to the first train and approaching it? what frequency (f recede) is heard by a passenger on a train moving at a speed of 18.0 m/s relative to the ground in a direction opposite to the first train and receding from it?