While john is traveling along a straight interstate highway, he notices that the mile marker reads 244 km. john travels until he reads the 135 km marker and the retraces his path to the 170 km marker. what is john's displacement from the 244 km marker?

absorption lines are where light has been absorbed by the atom thus you see a dip in the spectrum whereas.

emission spectra have spikes in the spectra due to atoms releasing photons at those wavelengths.

explanation:

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.